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slc 500™ universal analog input module

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1. 108 SLC 500 Universal Analog Input Module 24 Glawe G E Szaniszlo A J Long term drift of some noble and refractory metal thermocouples at 1600K in air argon and vacuum Temperature Its Measurement and Control in Science and Industry Vol 4 Plumb 11 H ed Pittsburgh Instrument Society of America 1972 1645 1662 25 Walker B E Ewing C T Miller R R Thermoelectric instability of some noble metal thermocouples at high temperatures Rev Sci Instrum 33 1029 1040 1962 26 Walker B E Ewing C T Miller R R Study of the instability of noble metal thermocouples in vacuum Rev Sci Instrum 36 601 606 1965 27 Bedford R E Ma C K Barber C R Chandler T R Quinn T J Burns G W Scroger M New reference tables for platinum 10 rhodium platinum and platinum 13 rhodium platinum thermocouples Temperature Its Measurement and Control in Science and Industry Vol 4 Plumb H H ed Pittsburgh Instrument Society of America 1972 1585 1603 28 Burns G W Strouse G F Mangum B W Croarkin M C Guthrie WE Marcarino P Battuello M Lee H K Kim J C Gam K S Rhee C Chattle M Arai M Sakurai H Pokhodun A I Moiseeva N P Perevalova S A de Groot M J Zhang J Fan K Wu S New reference functions for platinum 10 rhodium versus platinum type S thermocouples based on the ITS 90 Part I and Part II in Temperature Its
2. Appendix A Module Specifications 87 1000Q Pt 3916 RTD Example Deviations 0 25 0 E 2 3 Ch 7 Delta 25C N 0 25 4 Ch 7 Delta 60C FA e Ch 7 Delta OC HI o o 5 5 0 75 200 100 0 100 200 300 400 500 600 700 Degrees C RTD Input 10Q Cu 426 RTD Example Deviations E 2 3 Ch 7 Delta 25C Ch 7 Delta 60C FA Ch 7 Delta OC HI o o 100 50 0 50 100 150 200 250 300 Degrees C RTD Input 88 SLC 500 Universal Analog Input Module 120Q Ni 618 RTD Example Deviations E 2 3 H Ch 7 Delta 25C 8 Ch 7 Delta 60C 9 e CH7 Delta OC HI o o a 100 0 100 200 300 Degrees C RTD Input 1200 Ni 672 RTD Example Deviations E 5 3 Ch 7 Delta 25C a 4 Ch 7 Delta 60C 9 e Ch 7 Delta OC HI o o a 80 40 0 40 80 120 160 200 240 280 Degrees C RTD Input Appendix A Module Specifications 89 Millivolt volt and current The universal module supports many input paths in order to support the many different thermocouple RTD resistance millivolt volt and millamp input options Thus the hardware software errors of the system depends greatly upon the input path The following table provides the maximum error for each voltage or current input type when the module is operating at 25 C an
3. 0 12 6 Rung 2 8 Channel 7 Channel 7 Channel 7 Enable Open Alarm 12359 5 7 0 20 1 J E O 12 7 Figure 5 11 Data table for monitoring channel status bits Data Table address 15 data 0 address 15 data 0 N10 0 0000 0000 1001 0111 N10 4 0000 0000 1001 0111 N10 1 0000 0000 1001 0111 N10 5 0000 0000 1001 0111 N10 2 0000 0000 1001 0111 N10 6 0000 0000 1001 0111 N10 3 0000 0000 1001 0111 N10 7 0000 0000 1001 0111 Chapter 5 Ladder Program Examples 59 This is an example of how to automatically switch between reading the channel status words and channel data words Specifically this example shows a very simple method of utilizing a timer to periodically switch between reading the channel status and data words The program utilizes a timer accumulator value to determine when to set up the configuration words and when to read in the channel status and channel data information The channel status information is copied from the I 2 0 to 1 2 7 registers into registers N7 10 to N7 17 The channel data information is copied from 1 2 0 to 1 2 7 into registers N7 0 to N7 7 This allows sensor data and channel status information to be accessed at any time from these registers However when the module channels are configured to read sensor data the channel status words as reflected in N7 10 to N7 17 are not being dynamically updated and vice versa A longer interval between reading in the channel status information could be achieved thro
4. 0 2 0 1 0 0 1 0 2 0 3 0 4 0 5 Ch 7 Delta 25C amp Ch 7 Delta OC 6 Ch 7 Delta 60C 0 6 0 7 0 8 0 9 200 100 0 100 200 300 400 500 600 700 800 900 Degrees C RTD Input Appendix A Module Specifications 85 1000Q Pt 385 RTD Example Deviations 0 2 0 1 0 0 1 5 0 2 S 0 3 3 G m Ch 7 Delta 25C a U h 7 Delta 6 H Ch 7 Delta OC E 4 CH7 Delta 60C 0 6 amp 0 7 a 0 8 0 9 1 1 1 200 100 0 100 200 300 400 500 600 700 800 900 Degrees C RTD Input 100Q Pt 3916 RTD Example Deviations E 2 T 3 Ch 7 Delta 25C F 4 Ch 7 Delta OC 9 6 Ch 7 Delta 60C HI o a 200 100 0 100 200 300 400 500 600 700 Degrees C RTD Input 86 SLC 500 Universal Analog Input Module 200Q Pt 3916 RTD Example Deviations 0 3 0 2 0 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 Degrees C Deviation Degrees C RTD Input m Ch 7 Delta 25C 4 Ch 7 Delta OC Ch 7 Delta 60C 200 100 0 100 200 300 400 500 600 700 500Q Pt 3916 RTD Example Deviations 0 3 0 2 0 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 200 100 0 100 200 300 400 500 600 700 Degrees C RTD Input Degrees C Deviation Ch 7 Delta 25C Ch 7 Delta OC e Ch 7 Delta 60C
5. Channel 0 Disabled Channel 1 Disabled Channel 2 Disabled Channel 7 Disabled Sample CJC or Channel 0 Channel 1 Channel 2 Channel 7 Lead Resistance Calculate Calculate Previous Previous Calculate Calculate Previous Previous Update CJC The following table shows the channel sampling time for each filter frequency Table 3 2 Channel Sampling Time Channel Sampling Time for Each Filter Frequency all values 1 msec Channel Sampling Time 250 Hz Filter 60 Hz Filter 50 Hz Filter 10 Hz Filter 26 msec 64 msec 74 msec 314 msec The times above include a settling time necessary between input channel readings In addition on each module scan the module will sample either one CJC input or one lead resistance input if any enabled channel input type is a thermocouple RTD or resistance input The CJC sampling time is 64 msec The lead resistance sampling time is equal to the channel sampling time for that RTD When both thermocouple inputs and RTD or resistance inputs are used the module will alternate between sampling one CJC and one lead resistance The fastest module update time occurs when only one millivolt channel with a 250 Hz filter frequency is enabled Module update time 26 msec The slowest module update time occurs when eight channels four thermocouples and four RTDs each using a 10 Hz filter frequency are enabled Module update time 314 msec 314 msec 314 msec 314 msec 314 m
6. The difference between the maximum and minimum specified analog values Gain drift The change in full scale transition voltage measured over the operating temperature range of the module Input data scaling Depends on the data format that you select for the channel data work You can select from scaled for PID or Engineering Units for millivolt milliamp thermocouple RTD or CJC inputs which you must compute to fit your application s temperature or voltage resolution SLC 500 Universal Analog Input Modules Local System A control system with I O chassis within several feet of the processor and using 1746 C7 or 1746 C9 ribbon cable for communication LSB least significant bit The bit that represents the smallest value within a string of bits The weight of this value is defined as the full scale range divided by the resolution Mulitplexer A switching system that allows several input signals to share a common A D converter Normal mode rejection differential mode rejection A logarithmic measure in dB of a device s ability to reject noise signals between or among circuit signal conductors but not between the equipment grounding conductor or signal reference structure and the signal conductors Module update time See channel update time Remote system A control system shere the chassis can be located several thousand feet from the processor chassis Chassis communication is via the
7. These temperature limits apply to thermocouples used in conventional closed end protecting tubes and they are intended only as a rough guide to the user They do not apply to sheathed thermocouples having compacted mineral oxide insulation Nickel Chromium Alloy Versus Nickel Aluminum Alloy Thermocouples This type is more resistant to oxidation at elevated temperatures than types E J or T thermocouples and consequently it finds wide application at temperatures above 500 C The positive thermoelement KP which is the same as EP is an alloy that typically contains about 89 to 90 nickel 9 to about 9 5 chromium both silicon and iron in amounts up to about 0 5 plus smaller amounts of other constituents such as carbon manganese cobalt and niobium The negative thermoelement KN is typically composed of about 95 to 96 nickel 1 to 1 5 silicon to 2 3 aluminum 1 6 to 3 2 manganese up to about 0 5 cobalt and smaller amounts of other constituents such as iron copper and lead Also type KN thermoelements with modified compositions are available for use in special applications These include alloys in which the manganese and aluminum contents are reduced or eliminated while the silicon and cobalt contents are increased The low temperature research 8 by members of the NBS Cryogenics Division showed that the type K thermocouple may be used down to liquid helium temperatures about 4 K but that its Seebeck coefficient becomes
8. 120 140 160 180 200 50 100 150 200 250 300 Hz Signal Frequency SLC 500 Universal Analog Input Module Figure 3 4 Signal attenuation with 60 Hz input filter 308 HE 20 40 60 80 Amplitude in dB 0 120 140 160 180 200 0 60 120 180 240 300 360 Hz Y Signal Frequency 15 7 Hz Figure 3 5 Signal attenuation with 250 Hz input filter 308 20 40 60 80 Amplitude in dB 200 120 140 160 180 200 0 250 500 750 1000 1250 1500 Hz Signal Frequency 65 5 Hz Channel Step Response The channel filter frequency determines the channel s step response The step response is time required for the analog input signal to reach 95 of its expected final value given a full scale step change in the input signal This means that if an input signal changes faster than the channel step response a portion of that signal will be attenuated by the channel filter Table 6 shows the step response for each filter frequency Chapter 3 Things To Consider Before Using Your Module 29 Update Time The universal module update time is defined as the time required for the module to sample and convert the input signals of all enabled input channels and make the resulting data values available to the SLC processor It can be calculated by adding the sum of all enabled sample times plus one CJC update time or one lead resistance update time
9. 32 768 to 32 767 0 10 V 0 to 10 000 N A 0 to 16 383 32 768 to 32 767 10 V 10 000 to 10 000 N A 0 to 16 383 32 768 to 32 767 J 210 to 760 346 to 1 400 2 100 to 7 600 3 460 to 14 000 0 to 16 383 32 768 to 32 767 K 270 to 1 370 454 to 2 498 2 700 to 13 700 4 540 to 24 980 0 to 16 383 32 768 to 32 767 T 270 to 400 454 to 752 2 700 to 4 000 4 540 to 7 520 0 to 16 383 32 768 to 32 767 E 270 to 1 000 454 to 1 832 2 700 to 10 000 4 540 to 18 320 0 to 16 383 32 768 to 32 767 R 0 to 1 768 32 to 3 214 0 to 17 680 320 to 32 140 0 to 16 383 32 768 to 32 767 S 0 to 1 768 32 to 3 214 0 to 17 680 320 to 32 140 0 to 16 383 32 768 to 32 767 B 300 to 1 820 572 to 3 308 3 000 to 18 200 5 720 to 32 767 0 to 16 383 32 768 to 32 767 N 0 to 1 300 32 to 2 372 0 to 13 000 320 to 23 720 0 to 16 383 32 768 to 32 767 C 0 to 2315 32 to 4199 0 to 23 150 32 to 32767 0 to 16 383 32 768 to 32 767 100 Cu 426 100 to 260 148 to 500 1 000 to 2 600 1 480 to 5 000 0 to 16 383 32 768 to 32 767 120 Q Ni 618 100 to 260 148 to 500 1 000 to 2 600 1 480 to 5 000 0 to 16 383 32 768 to 32 767 120 Q Ni 672 80 to 260 112 to 500 800 to 2 600 1 120 to 5 000 0 to 16 383 32 768 to 32 767 3000Q 0 to 3 000 0 to 30 000 0 to 16 383 32 768 to 32 767 100Q Pt 385 200 to 850 328 to 1 562 2 000 to 8 500 3 280 to 15 620 0 to 16 383 32 768 to 32 767 200Q Pt 385 200 to 750 328 to 1 382 2 000 to 7 500 3 280 to 13 820 0 to 16 383 32 768 to 32 767
10. SLC 500 Universal Analog Input Module Figure 3 1 Image table Bit 0 Channel 0 Configuration Word Word 0 Channel 1 Configuration Word Word 1 Channel 2 Configuration Word Word 2 Channel 3 Configuration Word Word 3 Channel 4 Configuration Word Word 4 Channel 5 Configuration Word Word 5 Channel 6 Configuration Word Word 6 Channel 7 Configuration Word Word 7 Channel 0 Data or Status Word Word 0 Channel 1 Data or Status Word Word 1 Channel 2 Data or Status Word Word 2 Channel 3 Data or Status Word Word 3 Channel 4 Data or Status Word Word 4 Channel 5 Data or Status Word Word 5 Channel 6 Data or Status Word Word 6 Channel 7 Data or Status Word Word 7 Bit 15 Thermocouple SLC 5 0X Module Data Files Output Image Table EE Scan gt AEE Sorg eee Output Image Output Image 8 Words Input fa ae je Sm EE Input Image Input Image 8 Words Bit 15 Output Image Configuration Words Bit 0 Address 0 e 0 O e 1 0 e 2 03 O e 4 Deh 0 e 6 O e 7 l e 0 l e 1 l e 2 l e 3 l e 4 l e 5 l e 6 Ier Address Eight words of the SLC processor s output image table are reserved for the module Output image words 0 7 are used to configure the module s input channels 0 7 Each output image word configures a single channel and can be referred to as a configur
11. and explains the trade offs in using them with the NI8u module There are three 3 types of thermocouple junctions Grounded Junction The measuring junction is physically connected to the protective sheath forming a completely sealed integral junction If the sheath is metal or electrically conductive then there is electrical continuity between the junction and sheath The junction is protected from corrosive or erosive conditions The response time approaches that of the exposed junction type Ungrounded Junction The measuring junction is electrically isolated from the protective metal sheath This may also be referred to as an insulated junction This type is often used where noise would affect the reading and for frequent or rapid temperature cycling The response time is longer than the grounded junction Exposed Junction The measuring junction does not have a protective metal sheath so it is exposed This junction style provides the fastest response time but leaves the thermocouple wires unprotected against corrosive or mechanical damage The illustration that follows shows each of the three 3 thermocouple types Grounded Junction Extension Wire N Measuring Junction is Metal Sheath connected to sheath 114 SLC 500 Universal Analog Input Module Isolation Ungrounded Insulated Junction Measuring Junction is isolated from sheath Exposed Junction Measuring Junction has no sheath
12. 1 Open circuit No error 0 Open circuit detected 1 Under range No error 0 error Under range condition 1 Over Tange No error error Over range condition 1 Channel No error error Channel error 1 Chapter 4 Channel Configuration Data and Status 47 Channel 7 4 15 14 13 12 1110 9 8 7 6 5 4 3 2 1 Channel Channel disabled Status Channel enable 4 to 20 mA 0 to 20 mA 0 05 V E 0 10 V t 0 50 V 2 0 V 0to5 V Input lto5V Type 0 to 10 V 10V Thermocouple Type J Thermocouple Type K Thermocouple Type T Thermocouple Type E Thermocouple Type R Thermocouple Type S Thermocouple Type B Thermocouple Type N RTD 100 385 RTD 200 2 Pt 385 RTD 500 Q Pt 385 RTD 1000 Q Pt 385 RTD 100 Q Pt 3916 RTD 200 Q Pt 3916 RTD 500 Q Pt 3916 RTD 1000 Q Pt 3916 RTD 10 Q Cu 426 RTD 120 Q Ni 618 RTD 120 Q Ni 672 Resistance 3000 2 Thermocouple Type C CJC temperature ro o RB eh ken bah ee eee eee ee EEO e enen en COC COCO 5 5 0 0 0 2 2 0 0 5 00755 kon ben ben ben en en en bn O O CG Gi Ei E ben ben ben Fo Fa A bn Gi Ro ben 5 62 0 E Ei ben ben bn 60 CC E ben ben ben rn O OOO ra ra E CG 5 E ra Ei ba E ba OF OF OF OF OF OF OF OF Or OF OF Ei Fa Ei Engineering Units x1 0 0 Data Engineering Units x10 0 1 Format Scaled for PID 1 0 Proportional counts 1 1 Zero on open circuit 0 0 Open Max on open circuit 0 1 Circuit Min on open circuit 1 0 Disabled 1 1 Channel 10 HZ in
13. 30 K Temperature Scale EPT 76 4 The adoption of the ITS 90 has removed several deficiencies and limitations associated with IPTS 68 Temperatures on the ITS 90 are in closer agreement with thermodynamic values than were those of the IPTS 68 and EPT 76 Additionally improvements have been made in the non uniqueness and reproducibility of the temperature scale especially in the temperature range from t68 630 74 C to 1064 43 C where the type S thermocouple was the standard interpolating device on the IPTS 68 For additional technical information regarding ITS 90 refer to the NIST Monograph 175 Iron Versus Copper Nickel Alloy SAMA Thermocouples This is one of the most common types of industrial thermocouples because of its relatively high Seebeck coefficient and low cost It has been reported that more than 200 tons of type J materials are supplied annually to industry in this country However this type is least suitable for accurate thermometry because there are significant nonlinear deviations in the thermoelectric output of thermocouples obtained from different manufacturers These irregular deviations lead to difficulties in obtaining accurate calibrations based on a limited number of calibration points The positive thermoelement is commercially pure 99 5 Fe iron usually containing significant impurity levels of carbon chromium copper manganese nickel phosphorus silicon and sulfur Thermocouple wire represents suc
14. 43760 Sept 1987 for the 120Q Ni 618 RTD and MINCO Application Aid 18 May 1990 for the 120 Ni 672 RTD When configured for millivolt volt milliamp or resistance analog inputs the module converts the analog values directly into digital counts For those input types the module assumes that the input signal is linear prior to input into the module System Operation At power up the module checks its internal circuits memory and basic functions During this time the module status LED remains off If the module finds no faults it turns on its module status LED After completing power up checks the module waits for valid channel configuration data from your SLC ladder logic program channel status LEDs are off After channel configuration data is transferred and channel enable bits are set for one or more channels the module turns on its channel status LEDs Then it continuously converts the inputs to the data format you selected for the channel Each time the module reads an input channel the module tests that data for a fault i e over range or under range condition If open circuit detection is enabled the module tests for an open circuit condition If it detects an open circuit over range or under range condition the module sets a unique bit in the channel status word and causes the channel status LED to blink The SLC processor reads the converted thermocouple RTD resistance millivolt volt or milliamp data from the
15. 5000 Pt 385 200 to 850 328 to 1 562 2 000 to 8 500 3 280 to 15 620 0 to 16 383 32 768 to 32 767 1 0000 Pt 385 200 to 850 328 to 1 562 2 000 to 8 500 3 280 to 15 620 0 to 16 383 32 768 to 32 767 1000 Pt 3916 200 to 630 328 to 1 166 2 000 to 6 300 3 280 to 11 660 0 to 16 383 32 768 to 32 767 2000 Pt 3916 200 to 630 328 to 1 166 2 000 to 6 300 3 280 to 11 660 0 to 16 383 32 768 to 32 767 5000 Pt 3916 200 to 630 328 to 1 166 2 000 to 6 300 3 280 to 11 660 0 to 16 383 32 768 to 32 767 1 0000 Pt 3916 200 to 0 328 to 1 166 2 000 to 6 300 3 280 to 1 1660 0 to 16 383 32 768 to 32 767 CJC 25 to 105 13 to 221 250 to 1 050 130 to 2 210 0 to 16 383 32 768 to 32 767 When current voltage or resistance input types are selected the temperature setting is ignored and does not affect the data format When Type B or Type C thermocouples cannot be represented in engineering units x 1 in F above 3276 6 F the module s software will treat it as an over range condition if that channel has input to full scale 42 SLC 500 Universal Analog Input Module Table 4 4 1746sc NI8u Thermocouple Module Channel Data Word Resolution Data Format Input Engineering Units x 10 Engineering Units x 1 Scaled for PID Proportional Counts Type Celsius Fahrenheit Celsius Fahrenheit Celsius Fahrenheit Celsius Fahrenheit 0 001mA step 0 001mA step 1 221uA step 1 2211A step 0 3052uA step 0 3052uA step 4 2
16. 99 95 pure copper with an oxygen content varying from 0 02 to 0 07 depending upon sulfur content and with other impurities totaling about 0 01 Above about 200 C the thermoelectric properties of type TP thermoelements which satisfy the above conditions are exceptionally uniform and exhibit little variation between lots Below about 200 C the thermoelectric properties are affected more strongly by the presence of dilute transition metal solutes particularly iron The negative thermoelement TN or EN is a copper nickel alloy known ambiguously as constantan The word constantan refers to a family of copper nickel alloys containing anywhere from 45 to 60 copper These alloys also typically contain small percentages of cobalt manganese and iron as well as trace impurities of other elements such as carbon magnesium silicon etc The constantan for type T thermocouples usually contains about 55 copper 45 nickel and small but thermoelectrically significant amounts about 0 1 or larger of cobalt iron or manganese It should be emphasized that type TN or EN thermoelements are NOT generally interchangeable with type JN thermoelements although they are all referred to as constantan In order to provide some differentiation in nomenclature type TN or EN is often referred to as Adams or RP1080 constantan and type JN is usually referred to as SAMA constantan The thermoelectric relations for type TN and type EN thermoeleme
17. At each end of the cable strip some casing to expose individual wires 2 Trim signal wires to 5 inch lengths beyond the cable casing Strip about 3 16 inch 4 76 mm of insulation to expose the ends of the wires 3 At the module end of the cables see figure above Chapter 2 Installing And Wiring Your Module 19 extract the drain wire and signal wires remove the foil shield bundle the input cables with a cable strap 4 Connect pairs of drain wires together Channels 0 and 1 Channels 2 and 3 Channels 4 and 5 Channels 6 and 7 Keep drain wires as short as possible 5 Connect the drain wires to the shield inputs of the terminal block Channel 0 and I drain wires to the shield 0 1 input pin Channel 2 and 3 drain wires to the shield 2 3 input pin Channel 4 and 5 drain wires to the shield 4 5 input pin Channel 6 and 7 drain wires to the shield 6 7 input pin 6 Connect the signal wires of each channel to the terminal block Important Only after verifying that your connections are correct for each channel trim the lengths to keep them short Avoid cutting leads too short 7 Connect the chassis ground terminal lug to the nearest chassis mounting bolt with 14 gauge wire Looking at the face of the module the terminal lug is near the terminal block and above power supply PS2 on the primary side of the PCB 8 At the source end of cables from mV devices remove the drain wire and foil shield apply shrink wrap as an op
18. Cu 426 RTD 120Q Ni 618 RTD and 120Q Ni 672 RTD sensors 3000Q resistance devices and 50mV 100mV 500mV 2V 0 5V 1 5V 0 10V 10V 0 20mA and 4 20mA analog input signals The channel can also be configured to read the cold junction temperature calculated for that specific channel When the cold junction compensation CJC temperature is selected the channel ignores the physical input signal RTD and resistance inputs can only be supported by channels 4 7 Select Data Format Bits 6 and 7 The data format bit field lets you define the expressed format for the channel data word contained in the module input image The data types are engineering units scaled for PID and proportional counts The engineering units allow you to select from two resolutions x1 or x10 For engineering units x1 values are expressed in 0 1 degrees 0 01mV or 0 001mA For engineering units x10 values are expressed in 1 0 degrees ImV or 0 01mA Use the x10 setting to produce temperature readings in whole degrees Celsius or Fahrenheit You will notice in Table 11 that not all input types can support the x1 format The scaled for PID value is the same for millivolt milliamp thermocouple RTD resistance and CJC input types The input signal range is proportional to your selected input type and scaled into a 0 16 383 range which is standard to the SLC PID algorithm Chapter 4 Channel Configuration Data and Status 39 The pro
19. Guides E 1 What This Guide Covers ii ares 1 Related Allen Bradley Documents 1 Table A Related Allen Bradley documents i Terms amp Abbreviations You Should Know Ne i Chapter 1 General eap arere ESETE ger ESEE E e EEEE N ESERE 1 System EE 3 Compatibility with RTD and Resistance devices and cables cece 6 enrian Eana ekre se tepa Eea ai 7 Chapter 2 Electrostatic 0 9 Power E tanatorios 9 Shunt Configuration code 10 JP1 JP2 JP3 JP4 JPS JP6 JP7 and JP8 50 noresi 11 Current hie UE 11 Non Current E E EEEE E NEESER EEEE R EEES i 11 JPII EE 11 10 and JPI2 0 12 Setting For RTD or Resistance Inputs NEEN 12 Setting For Non RTD or Resistance Inputs Ne 12 Selecting A Rack 0 Er E EE 13 13 Wiring Your Module serende ieee aa 15 Wiring RTD or Resistance Sensors to the NI8u Module 16 Preparing and Witing the Cable 0 18 Chapter 3 IDC Oderrensrnoi ia n T TROE 23 23 Module iim 25 555 Channel Filter Frequency Selection Te TAES 29 Channel Turn On Turn Off and Reconfiguration Times es 30 Auto Cab Te 30 Response to Slot Disabling roserne nisn EREN NRE 32 Vi SLC 500 Universal Analog Input Modules Channel Configuration Data and Status Programming Examples Testing Your Module Maintaining Your Module And Ensuring Safety Appendices Chapter 4 Channel Commutation rata enden 35 Channel Configuration Procedure si
20. Programming Software APS Reference Manual 1747 6 3 Getting Started Guide for Advanced Programming Software APS ABT 1747 TSG001 SLC 500 Software Programmers s Quick Reference Guide 1747 NP002 Allen Bradley HHT Hand Held Terminal User Manual 1747 NM009 Getting Started Guide for HHT Hand Held Terminal SD499 Allen Bradley Publication Index AG 7 1 Allen Bradley Industrial Automation Glossary To obtain a copy of any of the Allen Bradley documents listed contact your local Allen Bradley office or distributor You should understand the following terms and abbreviations before using this guide A D Refers to analog to digital conversion The conversion produces a digital value whose magnitude is proportional to the instantaneous magnitude of an analog input signal Attenuation The reduction in magnitude of a signal as it passes through a system The opposite of gain Channel Refers to one of eight small signal analog input interfaces to the module s terminal block Each channel is configured for connection to a thermocouple or DC millivolt mV input device and has its own configuration and status words Chassis See rack Preface iii CJC Cold Junction Compensation The means by which the module compensates for the offset voltage error introduced by the temperature at the junction between the thermocouple lead wire and the input terminal block the cold junction Common mode rejection ratio CMRR
21. The NI8u module provides 12 5 VDC electrical isolation channel to channel 500 VDC electrical isolation channel to chassis ground and 500 VDC electrical isolation channel to backplane Care must be taken when choosing a thermocouple type and connecting it from the environment being measured to the NI8u module If adequate precautions are not taken for a given thermocouple type the electrical isolation of the NI8u module may be compromised Grounded Junction Thermocouples As shown in the illustration that follows the shield input terminals are connected together which are then connected to chassis ground Using grounded junction thermocouples with electrically conductive sheaths removes the thermocouple signal to chassis ground isolation of the module This is inherent to the thermocouple construction In addition if multiple grounded junction thermocouples are used the module s channel to channel isolation is removed since there is no isolation between signal and sheath and the sheaths are tied together It should be noted that the isolation is removed even if the sheaths are connected to chassis ground at a location other than the module since the module is connected to chassis ground For grounded junction thermocouples it is recommended that they have protective sheathes made of electrically insulated material e g ceramic or the metal protective sheaths be floated The metal sheaths would need to be floated with respect to any p
22. V 2 0 V 0to5V Input lto5 V Type 0 to 10 V 1 OV Thermocouple Type J Thermocouple Type K Thermocouple Type T Thermocouple Type E Thermocouple Type R Thermocouple Type S Thermocouple Type B Thermocouple Type N RTD 100 Q 385 RTD 200 Q Pt 385 RTD 500 Q Pt 385 RTD 1000 Q Pt 385 RTD 100 Q Pt 3916 RTD 200 Q Pt 3916 RTD 500 Q Pt 3916 RTD 1000 Q Pt 3916 RTD 10 Q Cu 426 RTD 120 Q Ni 618 RTD 120 Q Ni 672 Resistance 3000 Q Thermocouple Type C CJC Engineering Units x1 Data Engineering Units x10 Format Scaled for PID Proportional counts I 1 Zero on open circuit Max on open circuit Min on open circuit Disabled Degrees C Open Circuit Temperature Units Degrees F 1 Channel 10 Hz input filter filter 50 Hz input filter freq 60 Hz input filter 250 Hz input filter RTD Type 2 or 4 wire 3 wire Enabled Disabled Status word Auto cal Input Image Type Data_word 1 The configuration word default setting is all zeros Whan a voltage or current input type is selected the bit setting for temperature units is ignored Chapter 4 Channel Configuration Data and Status Table 4 2 15 14 13 12 11 10 9 0 0 1 1 0 0 0 1 1 OOo 1 0 oro 7 6 1 0 1 0 5 Sora 0o00o0ooooooooooooo0 4 Ra e Fe ben OOO OOOO OR en en ben ren ren ren ben COCO COCO COCO COD 3 S 0000 0000 0000 0000 2 ben E re ren E en ren 3 E ren ben
23. action you could take Topics include module and channel diagnostics LED indicators Interpreting I O error codes troubleshooting flowchart The module operates at two levels module level channel level Module level operation includes functions such as power up configuration and communication with the SLC processor ON indicates the module is OK OFF indicates a fault Channel level operation includes functions such as data conversion and open circuit detection ON indicates the channel is OK Blinking indicates a fault The module performs internal diagnostics at both levels and immediately indicates detected error conditions with either of its status LEDs When a status LED is continuously ON the status is OK Module Diagnostics at Power up At module power up the module performs a series of internal diagnostic tests If the module detects a failure its module status LED remains off Channel Diagnostics When a channel is enabled the module checks for a valid configuration Then on each scan of its inputs the module checks for out of range and open circuit fault conditions ofits inputs including the CJC input When the module detects a failure of any channel diagnostic test it causes the channel status LED to blink and sets the corresponding channel fault 64 SLC 500 Universal Analog Input Module LED Indicators bit bits 12 15 of the channel status word Channel fault bits and LEDs are
24. and 900 C and 1 7 C or 1 whichever is greater between 200 C and 0 C Type E thermocouples can also be supplied to meet special tolerances which are equal to 1 C or 0 4 whichever is greater between 0 C and 900 C and 1 C or 0 5 whichever is greater between 200 C and 0 C Type E thermocouple materials are normally supplied to meet the tolerances specified for temperatures above 0 C The same materials however may not satisfy the tolerances specified for the 200 C to 0 C range If materials are required to meet the tolerances below 0 C this should be specified when they are purchased The suggested upper temperature limit 870 C given in the ASTM standard 7 for protected type E thermocouples applies to AWG 8 3 25mm wire It decreases to 650 C for AWG 14 1 63mm 540 C for R Type Thermocouples AppendixB Thermocouple Descriptions 99 AWG 20 0 81mm 430 C for AWG 24 or 28 0 51mm or 0 33mm and 370 C for AWG 30 0 25mm These temperature limits apply to thermocouples used in conventional closed end protecting tubes and they are intended only as a rough guide to the user They do not apply to thermocouples having compacted mineral oxide insulation Platinum 13 Rhodium Alloy Versus Platinum Thermocouples This type is often referred to by the nominal chemical composition of its positive RP thermoelement platinum 13 rhodium The negative RN thermoelement is commercially available
25. at high temperatures gt 1200 C depends primarily upon the quality of the materials used for protection and insulation and has been studied by Walker et al 25 26 and by Bentley 29 High purity alumina with low iron content appears to be the most suitable material for insulating protecting and mechanically supporting the thermocouple wires Both thermoelements of type S thermocouples are sensitive to impurity contamination In fact type R thermocouples were developed essentially because of iron contamination effects in some British platinum 10 rhodium wires The effects of various impurities on the thermoelectric voltages of platinum based thermocouple materials have been described by Rhys and Taimsalu 35 by Cochrane 36 and by Aliotta 37 Impurity contamination usually causes negative changes 25 26 29 in the thermoelectric voltage of the thermocouple with time the extent of which will depend upon the type and amount of chemical contaminant Such changes were shown to be due mainly to the platinum thermoelement 25 26 29 Volatilization of the rhodium from the positive thermoelement for the vapor transport of rhodium from the positive thermoelement to the pure platinum negative thermoelement also will cause negative drifts in the thermoelectric voltage Bentley 29 demonstrated that the vapor transport of rhodium can be virtually eliminated at 1700 C by using a single length of twin bore tubing to insulate the thermoelements a
26. e atype B thermocouple may be registering a F value in EU x1 beyond the range allowed by the SLC processor beyond 32 767 for the data word e a CJC sensor may be damaged or the temperature being detected by the CJC may be outside the CJC sensor range limits e the millivolt Volt or milliamp input is outside ofits selected input range 66 SLC 500 Universal Analog Input Module Interpreting UO Error Codes Channel Error Bit 15 The module sets this fault bit when it detects any of the following Configuration erorrs configuration bits Data Format definition invalid Input Types for channels 0 through 3 10010 11101 configuration bits Data Format definition of Engineering Units x 1 for Input Types of 500mV 0 5V 1 5V 0 10V 10V 0 20mA configuration bits where Open Circuit is enabled with Input types of 0 SV 1 5V 0 10V 10V or 0 20mA invalid data acquisition of an input channel the filter frequency selected for the valid channel currently fails autocalibration range checks Module Status LED Green The module status LED indicates when the module detects a nonrecoverable fault at power up or during operation For this type of fault the module e no longer communicates with the SLC processor disables all channels clears all data and status words A module failure is non recoverable and requires the assistance of your local distributor or Spectrum Controls I O error codes ap
27. module will not function with any other CJC sensor connected 22 SLC 500 Universal Analog Input Module Module ID Code Module Addressing Chapter 3 Things To Consider Before Using Your Module This chapter explains how the module and the SLC processor communicate through the processor s I O image tables It also describes the module s input filter characteristics Topics discussed include module ID code module addressing channel filter frequency selection Channel turn on turn off and reconfiguration times response to slot disabling The module ID code is a unique number assigned to each type of 1746 I O module The ID defines for the processor the type of I O module and the number of words used in the processor s I O image table With APS software use the system I O configuration display to manually enter the module ID when assigning the slot number during the configuration Do this by selecting other from the list of modules on the system I O configuration display and enter 3500 the ID code for the 1746sc NI8u No special I O configuration SPIO CONFIG is required The module ID automatically assigns the correct number of input and output words If you are using different programming software package refer to the documentation that came with your software The following memory map shows you how the SLC processor s output and input tables are defined for the module 24
28. nisil respectively The research reported in NBS Monograph 161 showed that the type N thermocouple may be used down to liquid helium temperatures about 4 K but that its Seebeck coefficient becomes very small below 20 K Its Seebeck coefficient at 20 K is about 2 5uV K roughly one third that of type E thermocouples which are the most suitable of the letter designated thermocouples types for measurements down to 20 K Nevertheless types NP and NN thermoelements do have a relatively low thermal conductivity and good resistance to corrosion in moist atmospheres at low temperatures Type N thermocouples are best suited for use in oxidizing or inert atmospheres Their suggested upper temperature limit when used in conventional closed end protecting tubes is set at 1260 C by the ASTM 7 for 3 25mm diameter thermoelements Their maximum upper temperature limit is defined by the melting temperature of the thermoelements which are nominally 1410 C for type NP and 1340 C for type NN 5 The thermoelectric stability and physical life of type N thermocouples when used in air at elevated temperatures will depend upon factors such as the temperature the time at temperature the diameter of the thermoelements and the conditions of use Their thermoelectric stability and oxidation resistance in air have been investigated and compared with those of type K thermocouples by Burley 16 by Burley and others 13 44 47 by Wang and Starr 17 43 48 4
29. platinum that has a nominal purity of 99 99 21 An industrial consensus standard ASTM E1159 87 specifies that rhodium having a nominal purity of 99 98 shall be alloyed with platinum of 99 99 purity to produce the positive thermoelement which typically contains 13 00 0 05 rhodium by weight This consensus standard 21 describes the purity of commercial type R materials that are used in many industrial thermometry applications and that meet the calibration tolerances described later in this section It does not cover however the higher purity reference grade materials that traditionally were used to construct thermocouples used as transfer standards and reference thermometers in various laboratory applications and to develop reference functions and tables 22 23 The higher purity alloy material typically contains less than 500 atomic ppm of impurities and the platinum less than 100 atomic ppm of impurities 22 Differences between such high purity commercial material and the platinum thermoelectric reference standard Pt 67 are described in 22 and 23 A reference function for the type R thermocouple based on the ITS 90 and the SI volt was determined recently from new data obtained in a collaborative effort by NIST and NPL The results of this international collaboration were reported by Burns et al 23 The function was used to compute the reference table given in this monograph Type R thermocouples have about a 12 larger
30. power Are faulted channel s configured for mV or thermocouple input RTD or resistance Thermocouple Is more than one LED blinking Check channel status word CJC fault bits 12 15 has probably occurred Bit 15 set 1 Check that wiring is secure at both CJCs and that the temperature within the enclosure is in the range limits of the CJC sensor Refer to Chapter One Is problem corrected Contact you local distributor or Spectrum Controls Channel Channel Status LED s Status LED s off on Channel is Channel is not enabled enabled and working desired by setting channel config word bit 0 1 Retry Channel error Check configuration word for a valid input type configuration and insure bit 14 is set to zero Retry Bit 13 set 1 Contact you local distributor or i Spectrum gt 2 0 Controls Over range condition exists The input signal is greater than the high scale limit for Bit14 _ thechannelortheCJC gt set 1 connections Correct and Retry Under range condition exists The input signal is less than the low scale limit for the connections Correct and Retry An open circuit condition is present Check channel and CJC wiring for open or loose connections Chec
31. quite small below 20 K Its Seebeck coefficient at 20 K is only about 4uV K being roughly one half that of the type E thermocouple which is the most suitable of the letter designated thermocouples types for measurements down to 20 K Type KP and type KN thermoelements do have a relatively low thermal conductivity and good resistance to corrosion in moist atmospheres at low temperatures The thermoelectric 94 SLC 500 Universal Analog Input Module homogeneity of type KN thermoelements however was found 8 to be not quite as good as that of type EN thermoelements Type K thermocouples are recommended by the ASTM 5 for use at temperatures within the range 250 C to 1260 C in oxidizing or inert atmospheres Both the KP and the KN thermoelements are subject to deterioration by oxidation when used in air above about 750 C but even so type K thermocouples may be used at temperatures up to about 1350 C for short periods with only small changes in calibration When oxidation occurs it normally leads to a gradual increase in the thermoelectric voltage with time The magnitude of the change in the thermoelectric voltage and the physical life of the thermocouple will depend upon such factors as the temperature the time at temperature the diameter of the thermoelements and the conditions of use The ASTM Manual 5 indicates that type K thermocouples should not be used at high temperatures in sulfurous reducing or alternately oxid
32. the SLC 5 02 or later processor PID instruction without the need for an immediate scale operation Example Use NI8u channel data as the process variable in the PID instruction 1 Select scaled for PID as the data type in the channel configuration word 2 Specify the input channel data word as the process variable for the PID instruction In this example the value 32 617 is the numeric equivalent of configuration word N10 0 for channel 0 It is configured for a type K thermocouple scaled for PID zero the signal for an open circuit 10 Hz C channel enabled to return the data word Figure 5 8 Programming for PID Control Example Program Listing First Pass Bit Initialize NI8u Rung 2 0 Channel 0 Se MOV l MOVE 15 Source N10 0 32 617 Dest 03 0 0 Rung 2 1 PID PID Control Block N11 0 Process Variable 0 Control Variable N11 23 Control Block Length 23 Rung 2 2 SCL SCALE Source N11 23 Rate 10000 Offset Dest The Rate and Offset parameters should be set per Rung 2 3 your application analog output channel The Dest will typically be an Refer to the APS User Manual or Analog I O Modules User Manual for specific examples of the SLC instruction IEND I Chapter 5 Ladder Program Examples 57 Figure 5 9 Data table for PID Control Data Table address 15 data 0 address 15 data 0 N10 0 1000 0000 1001 0111 Monitoring Channel Status Bits Th
33. to eight inputs respectively that exist to support the 0 to 20mA or 4 to 20mA current input selections JP1 corresponds to channel 0 and JP8 corresponds to channel 7 The shunts of JP2 through JP7 follow for channels 1 through 6 respectively These shunts are two pin headers that only need to be connected if a channel is to be configured for current input If the channel is to be used for any other type thermocouple millivolt voltage for channels 0 through 3 or thermocouple millivolt voltage RTD or resistance for channels 4 through 7 then the pins are to be left open and unconnected Shunt removed Shunt in place Located in the bottom right hand corner JP11 should always have pins and 2 connected as shown This shunt is used during manufacturing of the module and should never be moved by the user 12 SLC 500 Universal Analog Input Module JP9 JP10 and JP12 Setup Setting For RTD or Resistance Inputs Setting For Non RTD or Resistance Inputs The NI8u module supports up to four RTD or resistance inputs on channels 4 through 7 In order to properly support RTD or resistance inputs JP9 JP10 and JP12 have to be configured correctly The function of JP9 and JP10 is to define the input path for the channels 4 through 7 JP9 and JP10 are four pin headers toward the right side of the board looking at the primary side of the board with the terminal block pointing up JP12 is a three pin header on the very bottom r
34. 0mA0 0 01mA step 0 01mA step 0 001mA step 0 001mA step 0 97661A step 0 97661A step 0 2441uA step 0 2441 A step 0 0 1mV step 0 01mV step 0 01mV step 6 1041 V step 6 1041 V step 1 526uV step 1 526uV step 0 01mV step 0 01mV step 12 21uV step 12 21uV step 3 052uV step 3 052uV step 61 04uV step 61 04uV step 15 261 V step 15 261 V step 0 001V step 0 01mV step 0 01mV step 244 1uV step 244 1uV step 61 041 V step 61 041 V step 0 001V step N A 244 1uV step 244 1uV step 61 04uV step 61 041 V step N gt 0 20mA 0 01mA step 0 01mA step 0 1mV step 0 100V 0 1mV step 0 1mV step 0 5VO 0 1mV step 0 1mV step 2 0VO 0 001V step zZ gt 0 5VO 0 001 V step step 030524 mae egen omvse 15264 egen 0 mVistp zen Lamae 15269V s egen omvse mee ovse Aan 61 04 7629 sep 7624Viste Looorviste Lage 30s20visep Bi Visp Lange vg 152 6 V step 30524V step 100 m r 385 0 02884F step P 385 0 02884F siep 2000 P 385 Lut 3000 Pt 385 Lut 10000 WAP 3916 002280 step MEET Lat P 3916 002280 ste 3000 Pt 3916 02280 F step 1008 Cu 2 000990 se 100 D nn 000990 se ANER 000998 se Leen 3000 y 0266 ste K 0 0450 F stp T 0 0184 F step E 0 0349 F step R 00486 Ftp s 0 0486 F step
35. 1747 SN Scanner and 1747 ASB Remote I O Adapter Resolution The smallest detectable change in a measurement typically expressed in engineering units e g 0 15 C or as a number of bits For example a 12 bit system has 4096 possible output states It can therefore measure part in 4096 See also effective resolution RTD Resistance Temperature Detector A temperature sensing element with 2 3 4 lead wires It uses the basic characteristics that electrical resistance of metals increases with temperature When a small current is applied to the RTD it creates a voltage that varies with temperature This voltage is processed and converted by the RTD module into a temperature value Sampling time The time required by the A D converter to sample an input channel Status word Contains status information about the channel s current configuration and operational state You can use this information in your ladder program to determine whether the channel data word is valid Step response time The time required for the A D signal to reach 95 of its expected final value given a full scale step change in the output data word Update time The time for the module to sample and convert a channel input signal and make the resulting value available to the SLC processor Module Overview Installing And Wiring Your Module Things To Consider Before Using Your Module Table of Contents Preface Who Should Use This
36. 2 7 17 1976 3 Mangum B W Furukawa G T Guidelines for realizing the International Temperature Scale of 1990 ITS 90 Natl Inst Stand Technol Tech Note 1265 1990 August 190 p 4 The 1976 Provisional 0 5 to 30 K Temperature Scale Metrologia 15 65 68 1979 5 ASTM American Society for Testing and Materials Manual on the use of thermocouples in temperature measurement Special Tech Publ 470B edited by Benedict R P Philadelphia ASTM 1981 258p 6 Hansen M Anderko K Constitution of binary alloys New York McGraw Hill Book Co 1958 7 ASTM American Society for Testing and Materials Standard E230 87 1992 Annual Book of ASTM Standards Vol 14 03 Philadelphia ASTM 1992 102 230 8 Sparks L L Powell R L Hall W J Reference tables for low temperature thermocouples Natl Bur Stand U S Monogr 124 1972 June 61p 9 Starr C D Wang T P Effect of oxidation on stability of thermocouples Proceedings of the American Society for Testing and Materials Vol 63 1185 1194 1963 10 Roeser W F Dahl A I Reference tables for iron constantan and copper constantan thermocouples J Res Natl Bur Stand U S 20 337 355 RP1080 1938 March 11 Dahl A I Stability of base metal thermocouples in air from 800 to 2200F J Res Natl Bur Stand U S 24 205 224 RP1278 1940 February 12 Sparks L L Powell R L Low temperatures thermocouples KP norm
37. 250Hz Filter 60Hz Filter 50Hz Filter 10Hz Filter Low 181mS 384mS 435mS 1 858 Mid 181mS 384mS 435mS 1 858 High 96mS 208mS 238mS 1 035 CJC sensors are acquired through the low voltage input path at 60Hz to maximize the trade offs between resolution and update rate Once every two minutes the module calibrates one of the input path and filter combinations on successive scans until all input path and filter combinations that are used have been calibrated During auto calibration the module scan time will increase by the auto calibration time Auto calibration can be disabled by placing a one in any enabled channel s auto cal disable bit 32 SLC 500 Universal Analog Input Module Response to Slot Disabling By writing to the status file in the modular SLC processor you can disable any chassis slot Refer to your SLC programming manual for the slot disable enable procedure CAUTION POSSIBLE EQUIPMENT OPERATION Always understand the implications of disabling a module before using the slot disable feature Failure to observe this precaution can cause unintended equipment operation Input Response When a universal slot is disabled the universal module continues to update its input image table However the SLC processor does not read input from a module that is disabled Therefore when the processor disables the universal module slot the module inputs appearing in the processor image table remain in their last st
38. 6 0 6 C 5002 Pt3916 0 5 C 10000 Pt3916 0 4 C 10Q Cu 426 3 0 C 1200 Ni618 0 4 C 120Q Ni672 0 4 C 30002 Resistance 2 00 Appendix A Module Specifications 83 The followingtable provides the maximum error for each RID and resistance type when the 10 Hz 50 Hz and 60 Hz filters are used and the module is operating at 0 C to 60 C and was at that temperature Errors due to lead wire resistance mismatches are not included Input Max Error Type 0 C to 60 C 100Q Pt 385 3 3C 2000 Pt 385 2 8 C 5000 Pt 385 3 0 C 1000Q Pt385 2 9 C 100Q Pt3916 0 200Q 6 0 5000 6 0 10002 Pt 3916 2 2 C 100 Cu 426 4 5 C 1200 Ni618 0 8 C 1200 Ni 2 0 8 C 30000 Resistance 7 0Q The diagrams that follow provide data from a sample module for a given RTD type over a range of inputs over temperature Degrees C Deviation 1002 Pt 385 RTD Example Deviations Ch 7 Delta 25C 4 Ch 7 Delta OC 0 Ch 7 Delta 60C 200 100 0 100 200 300 400 500 600 700 800 900 Degrees C RTD Input 84 SLC 500 Universal Analog Input Module Degrees C Deviation 200Q Pt 385 RTD Example Deviations 0 3 0 2 0 1 0 0 1 Ch 7 Delta 25C 4 Ch 7 Delta OC Ch 7 Delta 60C 0 2 0 3 0 4 0 5 0 6 0 7 0 8 200 100 0 100 200 300 400 500 600 700 0 Degrees C RTD Input Degrees C Deviation 500Q Pt 385 RTD Example Deviations
39. 9 by McLaren and Murdock 33 by Bentley 19 and by Hess 50 Type N thermocouples in general are subject to the same environmental restrictions as types E and K They are not recommended for use at high temperatures in sulfurous reducing or alternately oxidizing and reducing atmospheres unless suitably protected with protecting tubes They also should not be used in vacuum at high temperatures for extended times because the chromium and silicon in the positive thermoelement a nickel chromium silicon alloy vaporize out of solution and alter the calibration In addition their use in atmospheres with low but not negligible oxygen content is not recommended since it can lead to changes in calibration due to the preferential oxidation of chromium in the positive thermoelement Nevertheless Wang and Starr 49 studied the performances of type N thermocouples in reducing atmospheres as well as in stagnant air at temperatures in the 870 C to 1180 C range and found them to be markedly more stable thermoelectrically than type K thermocouples under similar conditions AppendixB Thermocouple Descriptions 105 The performance of type N thermocouples fabricated in metal sheathed compacted ceramic insulated form also has been the subject of considerable study Anderson and others 51 Bentley and Morgan 52 and Wang and Bediones 53 have evaluated the high temperature thermoelectric stability of thermocouples insulated with magnesiu
40. 90 for the 120Q Ni 672 RTD Thermocouple NIST ITS 90 standard Linearization Channel Multiplexing 3mS Settling Time RTD Current Source 200pA one for each RTD channel Cold Junction Accuracy 1 72 C 25 C to 105 Compensation On board CJC Sensor Required Analog Devices AD592CN Input Impedence Greater than 10MQ gt Ohm Voltage Thermocouple RTD gt 250 Q current Temperature Scale C of F and 0 1 C or 0 1 F Selectable DC Millivolt Scale 0 1 mV 0 01 mV or 0 001 mV Selectable Depending on input type Milliamp Scale 01 mA or 001mA Selectable Open Circuit Detection Upscale Downscale Zero or Disabled Selectable Does not apply to 5 or 10V range or 0 20mA input type Time to Detect One module update time Open Circuit Input Step Response 0 to 95 in 300 msec 10 Hz Display Resolution See Channel Data Word Resolution table in Chapter 4 Overall Module Accuracy See Module Accuracy Tables below 25 C 77 F Overall Module Accuracy See Module Accuracy Tables below 0 C to 60 C 32 F to 140 F Overall Module Drift See Module Accuracy Tables below Module Update Time Dependent upon enabled channels see Update Time Chap 3 Channel Turn Off Time Up to one module update time Overall Accuracy The accuracy of the module is determined by many aspects of the hardware and software functionality of the module The following attempts to explain what the user can expect in terms of accuracy based on the
41. B 0 0417 F step N 0 0357 F step c 0 0636 F step CIC 0 0079 C step 0 0036 F step Sensor When millivolts or resistance are selected the temperature setting is ignored Analog input data is the same for either C or F selection Chapter 4 Channel Configuration Data and Status 43 Important Data resolution is not equivalent to data accuracy Data resolution merely indicates what a bit weight is in any given input type and data format combination Input accuracy of 50u V may span multiple steps for PID and Proportional Counts data types As an example a Type B thermocouple temperature range of 0 to 1820 C provides a voltage input range of 0 to 13 82mV to the NI8u This is a very small input range and when it is scaled to PID or proportional counts ranges a small input change will result in many counts being changed Select Open Circuit State Bits 8 and 9 The open circuit bit field lets you define the state of the channel data word when an open circuit condition is detected for that channel The open circuit does not apply to the 0 5V 1 5 V 0 10V 2V 10V or 0 20mA input types and should be disabled when those types are selected or else a configuration error will result It can be enabled for all other types including the CJC input This feature can be disabled by selecting the disable option An open circuit condition occurs when the input path is physically separated or open For the
42. C 500 Universal Analog Input Module Thermocouple Type K Example Deviations High Range Degrees C Deviation E 2 5 3 Ch 2 Delta 25C o Ch 2 Delta OC 9 e Ch 2 Delta 60C o o A 200 0 200 400 600 800 1000 1200 0 Degrees C TC Input Thermocouple Type T Example Deviations Low Range 0 5 Ch 2 Delta 25 C 4 Ch 2 Delta OC Ch 2 Delta 60C 250 240 230 220 210 200 Degrees C TC Input Appendix A Module Specifications 79 0 05 Thermocouple Type T Example Deviations High Range Degrees C Deviation Ch 2 Delta 25 C Ch 2 Delta OC Ch 2 Delta 60C 200 100 0 100 200 300 400 Degrees C TC Input 025 o Thermocouple Type E Example Deviations Degrees C Deviation oS 98 o E N o oo 1 270 170 70 30 130 230 330 430 530 630 730 830 930 1030 m Ch 2 Delta 25C E SC E EE A A Ch 2 Delta 0C e Ch 2 Delta 60C Degrees C TC Input 80 SLC 500 Universal Analog Input Module Thermocouple Type R Example Deviations gl Degrees C Deviation Degrees CTC Input 0 200 400 600 800 1000 1200 1400 1600 1800 Ch 2 Delta 25C 4 Ch 2 Delta OC Ch 2 Delta 60C Thermocoupl
43. E E ren en CO CO ren ren E CO ben ben E E ren ren CO CH 1 37 Channel Configuration Word O e 7 4 38 SLC 500 Universal Analog Input Module Select Channel Enable Bit 0 Use the channel enable bit to enable a channel The universal module only scans those channels that are enabled To optimize module operation and minimize throughput times unused channels should be disabled by setting the channel enable bit to zero When set 1 the channel enable bit is used by the module to read the configuration word information you have selected While the enable bit is set modification of the configuration word may lengthen the module update time for one cycle If any change is made to the configuration word the change will be reflected in the status word before new data is valid described in the last section of this chapter While the channel enable bit is cleared 0 the associated channel data status word values are cleared After the channel enable bit is set the associated channel data status word remains cleared until the universal module sets the channel status bit bit 0 in the channel status word Select Input Types Bits 1 5 The input type bit field lets you configure the channel for the type of input device you have connected to the module Valid input devices are types J K T E R S B N and C thermocouple sensors 1000 200Q 5000 and 1000Q Pt 385 RTDs 1002 2009 5000 and 1000Q Pt 3916 RTDs 10Q
44. EXC5 CH5 CH5 EXC5 CJCB CJCB CJC A CJC A CH2 CH2 Shield for CH2 and CH3 CH3 CH3 EXC6 CH6 CH6 EXC6 Shield for CH6 and CH7 EXC7 CH7 CH7 EXC7 Chapter 2 Installing And Wiring Your Module 21 The module also has a ground terminal TB1 which should be grounded to a chassis mounting bolt with 14 gauge wire Cold Junction Compensation CJC CAUTION POSSIBLE EQUIPMENT OPERATION Do not remove or loosen the cold junction compensating temperature transducers located on the terminal block unless you are connecting remote CJCs to the module Both CJCs are critical to ensure accurate thermocouple input readings at each channel The module will not operate in thermocouple mode if a CJC is not connected Failure to observe this precaution can cause unintended equipment operation and damage To obtain accurate readings from each of the channels the cold junction temperature temperature at the module s terminal junction between the thermocouple wire and the input channel must be compensated for Two cold junction compensating sensors have been integrated in the removable terminal block They must remain installed to retain accuracy If remote CJC compensation is desired the sensors at the terminal block must be removed and the external sensors wired to the CJCA and CJCB terminals The remote CJC sensors must be Analog Devices AD592CN T0 92 style temperature transducer devices The
45. F to 1562 F Type Platinum 385 100 Ohm 200 Ohm 500 Ohm 1000 Ohm 200 C to 850 C 328 F to 1562 F Platinum 3916 100 Ohm 200 C to 630 C 328 F to 1166 F 200 C to 630 C 328 F to 1166 F 200 C to 630 C 328 F to 1166 F 200 C to 630 C 328 F to 1166 F 100 C to 260 C 148 F to 500 F 100 C to 260 C 148 F to 500 F 200 Ohm 500 Ohm 1000 Ohm Copper 426 10 Ohm Nickel 618 120 Ohm Nickel 672 120 Ohm 80 C to 260 C 112 F to 500 F 1 The digits following the RTD type represent the temperature coefficient of resistance alpha a which is defined as the resistance change per Ohm per C For instance Platinum 385 refers to a platinum RTD with a 0 00385 Ohms Ohm 0 00385 C Table 1 3 Millivolt Input Ranges 50 to 50 mV 100 to 100 mV 500 to 500 mV 2 0 to 2 0 V 0 to 5 0 V 1 0 to 5 0 V 0 to 10 0 V 10 0 to 10 0 V Table 1 4 Current Input Ranges 4 to 20 mA 0 to 20 mA Table 1 5 Resistance Input Range 0 to 3000 Ohms C or simply System Overview Chapter 1 Module Overview 3 All eight input channels are individually configurable for thermocouple millivolt volt or milliamp input types Channels 4 through 7 can be defined for RTD or resistance inputs and then can be individually configured for a specific RTD or resist
46. F to 140 F 40 C to 85 C 40 F to 185 F 5 to 95 without condensation UL amp CUL approved Class1 Division 2 Hazardous Environment Groups A B C D CE compliant Thermocouple Type J 210 Cto760 C 346 Fto 1400 F Thermocouple Type K 270 C to1370 C 454 F to 2498 F Thermocouple Type 270 Cto400 C 454 F to 752 F Thermocouple Type E 270 C to 1000 C 454 F to 1832 F Thermocouple TypeR 0 C to 1768 C 32 F to 3214 F Thermocouple TypeS 0 C to 1768 C 32 F to 3214 F Thermocouple Type 300 C to1820 C 572 F to 3308 F Thermocouple Type N 0 C to 1300 C 32 F to 2372 F Thermocouple Type 6 0 C to 2315 C 32 F to 4199 F Millivolt 50 mVdc to 50 mVdc Millivolt 100 mVdc to 100 mVdc Millivolt 500mV 2V 0 5V 1 5V 0 10V 10V Current 4 to 20mA Current 0 to 20mA RTD Pt 385 200 Ct0 85070 328 F to 1562 F 1002 5002 10002 RTD Pt 385 200 C to 750 C 328 F to 1382 F 2000 RTD Pt 3916 200 C to 630 C 328 F to 1166 F 100 2002 5002 10000 RTD 100 Cu 426 100 C to 260 C 148 F to 500 F RTD 120Q Ni 618 100 C to 260 C 148 F to 500 F RTD 120Q Ni 672 80 C to 260 C 112 F to 500 F Resistance 0 to 30000 Appendix A Module Specifications 75 RTD Conversion JIS C 1602 1997 for Pt 385 JIS C 1604 1989 for Pt 3916 SAMA RC21 4 1966 for the 108 Cu 426 RTD DIN 43760 Sept 1987 for the 1209 Ni 618 RTD MINCO Application Aid 18 May 19
47. Measurement and Control in Science and Industry Vol 6 Schooley J F ed New York American Institute of Physics 1992 537 546 29 Bentley R E Changes in Seebeck coefficient of Pt and Pt 10 Rh after use to 1700C in high purity polycrystalline alumina nt J Thermophys 6 1 83 99 1985 30 McLaren E H Murdock E G New considerations on the preparation properties and limitations ofthe standard thermocouple for thermometry Temperature Its Measurement and Control in Science and Industry Vol 4 Plumb H H ed Pittsburgh Instrument Society of America 1972 1543 1560 31 McLaren E H Murdock E G The properties of Pt PtRh thermocouples for thermometry in the range 0 1100C I Basic measurements with standard thermocouples National Research Council of Canada Publication APH 2212 NRCC 17407 1979 32 McLaren E H Murdock E G The properties of Pt PtRh thermocouples for thermometry in the range 0 1100C II Effect of heat treatment on standard thermocouples National Research Council of Canada Publication APH 2213 NRCC 17408 1979 AppendixB Thermocouple Descriptions 109 33 McLaren E H Murdock E G Properties of some noble and base metal thermocouples at fixed points in the range 0 1100C Temperature Its Measurement and Control in Science and Industry Vol 5 Schooley J F ed New York American Institute of Physics 1982 953 975 34 Bentley R E Jones T P Inhomogeneities
48. Owner sGuide 0300172 03 Rev D SLC 500 UNIVERSAL ANALOG INPUT MODULE Thermocouple RTD Resistance mV V mA Catalog Numbers 1746sc NI8u pai fa f U il Bo CH eJ o L 5 R Important Notes 1 Please read all the information in this owner s guide before installing the product 2 The information in this owner s guide applies to hardware series B and firmware version 2 0 or later 3 This guide assumes that the reader has a full working knowledge of the relevant processor Notice The products and services described in this owner s guide are useful in a wide variety of applications Therefore the user and others responsible for applying the products and services described herein are responsible for determining their acceptability for each application While efforts have been made to provide accurate information within this owner s guide Spectrum Controls assumes no responsibility for the accuracy completeness or usefulness of the information herein Under no circumstances will Spectrum Controls be responsible or liable for any damages or losses including indirect or consequential damages or losses arising out of either the use of any information within this owner s guide or the use of any product or service referenced herein No patent liability is assumed by Spectrum Controls with respect to the use of any of the information products circuits programming or services re
49. SI DIVISION2 WARNING EXPLOSION HAZARD DO NOT DISCONNECT EQUIPMENT UNLESS POWER HAS BEEN SWITCHED OFF OR THE AREA IS KNOWN TO BE NON HAZARDOUS NOTE THIS EQUIPMENT IS SUITABLE FOR USE IN CLASSI DIVISION 2 GROUPS A B C AND D OR NON HAZARDOUS LOCATIONS ONLY Chapter 7 Maintaining Your Module And Ensuring Safety 71 WARNING EXPLOSION HAZARD WHEN IN HAZARDOUS LOCATIONS TURN OFF POWER BEFORE REPLACING OR WIRING MODULES WARNING THIS DEVICE IS INTENDED TO ONLY BE USED WITH THE ALLEN BRADLEY SLC500 SYSTEMS Refer to your system s Installation amp Operation Manual for more information 72 SLC 500 Universal Analog Input Module Electrical Specifications Appendix A Module Specifications This appendix lists the specifications for the 1746sc NI8u Universal analog Input Module Backplane Current Consumption Backplane Power Consumption Number of Channels I O Chassis Location AD Conversion Method Input Filtering Normal Mode Rejection between input and input Common Mode Rejection between inputs and chassis ground Input Filter Cut Off Frequencies Calibration Input Overvoltage Protection Input Overcurrent Protection Isolation 120 mA at 5 VDC 100 mA at 24 VDC 3 00W maximum 0 6W 5 VDC 2 4W 24 VDC 8 backplane and channel to channel isolated Any I O module slot except 0 Sigma Delta Modulation Low pass digital filter with programmable notc
50. Seebeck coefficient than do Type S thermocouples over much of the range Type R thermocouples were not standard interpolating instruments on the IPTS 68 for the 630 74 C to gold freezing point range Other than these two points and remarks regarding history and composition all of the precautions and restrictions on usage given in the section on type S thermocouples also apply to type R thermocouples Glawe and Szaniszlo 24 and Walker et al 25 26 have determined the effects that prolonged exposure at elevated temperatures gt 1200 C in vacuum air and argon atmospheres have on the thermoelectric voltages of type R thermocouples ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for type R commercial thermocouples be 1 5 C or 0 25 whichever is greater between 100 SLC 500 Universal Analog Input Module S Type Thermocouples 0 C and 1450 C Type R thermocouples can be supplied to meet special tolerances of 0 6 C or 0 1 whichever is greater The suggested upper temperature limit 1480 C given in the ASTM standard 7 for protected type R thermocouples applies to AWG 24 0 5 1mm wire This temperature limit applies to thermocouples used in conventional closed end protecting tubes and it is intended only as a rough guide to the user It does not apply to thermocouples having compacted mineral oxide insulation Platinum 10 Rhodium Alloy Ve
51. The ratio of a device s differential voltage gain to common mode voltage gain Expressed in dB CMRR is a comparative measure of a device s ability to reject interference caused by a voltage common to its terminal relative to ground Common mode voltage The voltage difference between the negative terminal and analog common during normal differential operation Configuration word Contains the channel configuration information needed by the module to configure and operate each channel Information is written to the configuration word through the logic supplied in your ladder program Cut off frequency The frequency at which the input signal is attenuated 3 dB by the digital filter Frequency components of the input signal that are below the cut off frequency are passed with under 3 dB of attenuation for low pass filters dB decibel A logarithmic measure of the ratio of two signal levels Data word A 16 bit integer that represents the value of the analog input channel The channel data word is valid only when the channel is enabled and there are no channel errors Digital filter A low pass filter of the A D converter The digital filter provides high frequency noise rejection Effective resolution The number of bits in the channel data word that do not vary due to noise Full scale error gain error The difference in slope between the actual and ideal analog transfer functions Full scale range FSR
52. York American Institute of Physics 1982 1147 1157 50 Hess T G Nicrosil nisil high performance thermocouple alloys ISA Transactions 16 3 81 84 1977 51 Anderson R L Lyons J D Kollie T G Christie W H Eby R Decalibration of sheathed thermocouples Temperature lts Measurement and Control in Science and Industry Vol 5 Schooley J F ed New York American Institute of Physics 1982 977 1007 52 Bentley R E Morgan T L Ni based thermocouples in the mineral insulated metal sheathed format thermoelectric instabilities to 1100C J Phys E Sci Instrum 19 262 268 1986 53 Wang T P Bediones D 10 000 hr stability test of types K N and a Ni Mo Ni Co thermocouple in air and short term tests in reducing atmospheres Temperature lts Measurement and Control in Science and Industry Vol 6 Schooley J F ed New York American Institute of Physics 1992 595 600 54 Burley N A N CLAD N A novel advanced type N integrally sheathed thermocouple ofultra high thermoelectric stability High Temperatures High Pressures 8 609 616 1986 55 Burley N A A novel advanced type N integrally sheathed thermocouple of ultra high thermoelectric stability Thermal and Temperature Measurement in Science and Industry 3rd Int IMEKO Conf Sheffield Sept 1987 115 125 56 Burley A N CLAD N A novel integrally sheathed thermocouple optimum design rationale for ultra high the
53. al silver and copper versus Au 0 02 at Fe and Au 0 07 at Fe J Res Natl Bur Stand U S 76A 3 263 283 1972 May June 13 Burley N A Hess R M Howie C F Coleman J A The nicrosil versus nisil thermocouple A critical comparison with the ANSI standard letter designated base metal thermocouples Temperature Its Measurement and Control in Science and Industry Vol 5 Schooley J F ed New York American Institute of Physics 1982 1159 1166 AppendixB Thermocouple Descriptions 107 14 Potts J F Jr McElroy D L The effects of cold working heat treatment and oxidation on the thermal emf of nickel base thermoelements Herzfeld C M Brickwedde F G Dahl A I Hardy J D ed Temperature Its Measurement and Control in Science and Industry Vol 3 Part 2 New York Reinhold Publishing Com 1962 243 264 15 Burley N A Ackland R G The stability of the thermo emf temperature characteristics of nickel base thermocouples Jour of Australian Inst of Metals 12 1 23 31 1967 16 Burley N A Nicrosil and nisil Highly stable nickel base alloys for thermocouples Temperature Its Measurement and Control in Science and Industry Vol 4 Plumb H H ed Pittsburgh Instrument Society of America 1972 1677 1695 17 Wang T P Starr C D Electromotive force stability of nicrosil nisil Journal of Testing and Evaluation 8 4 192 198 1980 18 Starr C D Wang T P Effec
54. ance type Each input channel provides broken input over range and under range detection and indication when enabled Hardware Features The module fits into any single slot for I O modules in either an SLC 500 modular system or an SLC 500 fixed system expansion chassis 1746 A2 It is a Class 1 module uses 8 input words and 8 output words Requires use of Block Transfer in a remote configuration The module utilizes two removable terminal blocks that provides connections for the eight input channels There are two cold junction compensation CJC sensors that compensate for the cold junction at ambient temperature rather than at freezing 0 C There are four current sources for supplying the RTD or resistance sensors The module is configured through software with jumpers used to define RTD resistance current or voltage input paths Table 1 6 Hardware Features Hardware Function Channel Status LED Indicators Display operating and fault status of channels 0 7 Module Status LED Displays operating and fault status of the module Side Label Nameplate Provides module information Removable Terminal Block Provides electrical connection to input devices Door Label Permits easy terminal identification Self Locking Tabs Secure module in chassis slot Diagnostic LEDs The module contains diagnostic LEDs that help you identify the source of problems that may occur during power up or during normal operation Power up and ch
55. annel Data Word Format table Siow 454 F an d Sj on 1832 F Solution Engr Units Equivalent 454 F 1832 F 454 F x 21567 32768 65536 1441 3 F Engineering Units to Proportional Counts Equation Proportional Counts Equivalent 65536 x Engineering Units desired S ow S ue Di vull 32768 Assume type E input type proportional counts display type desired channel temp 1000 F Want to calculate Proportional Counts equivalent From Channel Data Word Format table Siow 454 F and S 1832 F HIGH Solution Proportional Counts Equivalent 65536 x 1000 F 454 F 1832 F 454 F 32768 8916 Chapter 4 Channel Configuration Data and Status 41 Table 4 3 1746sc NI8u Universal Module Channel Data Word Format Data Format Input Engineering Units x 10 Engineering Units x 1 Proportional Type Celsius Fahrenheit Celsius Fahrenheit Scaled for PID ounts 4 20 mA 400 to 2 000 4 000 to 20 000 0 to 16 383 32 768 to 32 767 0 20 mA 0 to 2 000 0 to 20 000 0 to 16 383 32 768 to 32 767 0 05 V 500 to 500 5 000 to 5 000 0 to 16 383 32 768 to 32 767 0 10 V 1 000 to 1 000 10 000 to 10 000 0 to 16 383 32 768 to 32 767 0 50 V 5 000 to 5 000 NA 0 to 16383 32 768 to 32 767 2 0V 2 000 to 2 000 20 000 to 20 000 0 to 16 383 32 768 to 32 767 0 5 Y 0 to 5 000 NA 0 to 16 383 32 768 to 32 767 1 5 Y 1 000 to 5 000 NA 0 to 16 383
56. annel diagnostics are explained in Chapter 6 Testing Your Module The module communicates with the SLC 500 processor and receives 5 Vde and 24 Vdc power from the system power supply through the parallel backplane interface No external power supply is required You may install as many universal modules in the system as the power supply can support SLC 500 Universal Analog Input Module The first four input channels 0 through 3 can receive input signals from thermocouples millivolt volt or milliamp devices The last four input channels 4 through 7 can receive input signals from thermocouples millivolt volt milliamp or 2 3 or 4 wire RTD or resistance devices If RTD or resistance inputs are selected channels 4 through 7 can be individually configured for the supported RTD or resistance types When configured for thermocouple input types the module converts analog input voltages into cold junction compensated and linearized digital temperature readings The module uses the National Institute of Standards and Technology NIST linearization tables based on ITS 90 for thermocouple linearization When configured for RTD input types the module converts the analog input voltages into digital temperature readings based on the alpha type wire type and ohms specified The standards used are the JIS C 1604 1997 for the Pt 385 RTD types the JIS C 1604 1989 for the Pt 3916 RTD types SAMA RC21 4 1966 for the 10Q Cu 426 RTD DIN
57. as a rough guide to the user They do not apply to thermocouples having compacted mineral oxide insulation Nickel Chromium Alloy Versus Copper Nickel Alloy Thermocouples This type and the other base metal types do not have specific chemical compositions given in standards rather any materials whose emf temperature relationship agrees with that of the specified reference table within certain tolerances can be considered to be a type E thermocouple The positive thermoelement EP is the same material as KP The negative thermoelement EN is the same material as TN The low temperature research 8 by members of the NBS Cryogenics Division showed that type E thermocouples are very useful down to liquid hydrogen temperatures n b p about 20 3 K where their Seebeck coefficient is about 8uV C They may even be used down to liquid helium temperatures 4 2 K although their Seebeck coefficient becomes quite low only about 2uV C at 4 K Both thermoelements of type E thermocouples have a relatively low thermal conductivity good resistance to corrosion in moist atmospheres and reasonably good homogeneity For these three reasons and their relatively high Seebeck coefficients type E thermocouples have been recommended 8 as the most useful of the letter designated thermocouple types for low temperature measurements For measurements below 20 K the non letter designated thermocouple KP versus gold 0 07 at iron is recommended The p
58. ate and the module s updated image table is not read When the processor re enables the module slot the current state of the module inputs are read by the processor during the subsequent scan Output response The SLC processor may change the universal module output data configuration as it appears in the processor output image However this data is not transferred to the universal module The outputs are held in their last state When the slot is re enabled the data in the processor image is transferred to the universal module Channel Configuration Chapter 4 Channel Configuration Data and Status Read this chapter to configure each input channel check each input channel s configuration and status Channel configuration words appear in the SLC controller s output image table as shown below Words 0 7 correspond to module channels 0 7 After module installation you must configure each channel to establish the way the channel operates e g input type temperature units etc You configure the channel by setting bits in the configuration word using your programmer We present bit descriptions next SLC Output Image Configuration Words 15 0 Channel 0 Configuration Word 1 1 1 1 1 1 1 Channel 1 Configuration Word Channel 2 Configuration Word Channel 3 Configuration Word Channel 4 Configuration Wo
59. ates how you have defined the open circuit bits configuration word and therefore the response of the universal module to an open circuit condition This feature does not apply to the 0 5 V 1 5 V 0 10 V 2 V 10 V or 0 20mA input ranges and a properly configured channel of those types will give the disabled status It applies to all others including CJC temperature input Channel Filter Frequency Bits 10 and 11 The channel filter frequency bit field reflects the filter frequency you selected in the configuration word Open Circuit Error Bit 12 This bit is set 1 whenever a configured channel detects an open circuit condition at its input Short circuited RTD inputs will also flag this error condition A short circuit for RTDs exist when the module reads less than 3 ohms across the RTD input An open circuit at the CJC sensor will also flag this error if the channel input type is either thermocouple or CJC temperature A range error on the CJC sensor will also flag this bit if the input type is a thermocouple type Chapter 4 Channel Configuration Data and Status 49 Under Range Error Bit 13 This bit is set 1 whenever a configured channel detects an under range condition for the channel data An under range condition exists when the input value is equal to or below the specified lower limit of the particular sensor connected to that channel Over Range Error Bit 14 This bit is set 1 whenever a configur
60. ath to chassis ground or to another thermocouple metal sheath This means the metal sheath must be insulated from electrically conductive process material and have all connections to chassis ground broken It should be noted that a floated sheath may result in a less noise immune thermocouple signal Appendix B Using Grounded Junction Ungrounded Junction and Exposed Junction Thermocouples 115 1746sc NI8u Grounded junction with shielded cable Metal sheath with electrical continuity to thermocouple signal wires Exposed Junction Thermocouples As shown in the illustration that follows using exposed junction thermocouples may result in removal of channel to channel isolation This may occur if multiple exposed thermocouples are in direct contact with electrically conductive process material To prevent violation of channel to channel isolation 116 SLC 500 Universal Analog Input Module e For multiple exposed thermocouples do not allow the measuring junction of the thermocouple to make direct contact with electrically conductive process material e Use a single exposed junction thermocouple with multiple ungrounded junction thermocouples Use all ungrounded junction thermocouple instead of the exposed junction type 1746sc NI8u Conductive Material Exposed junction with shielded cable Getting Technical Assistance Declaration of Conformity If you need technical assistance please review the informati
61. ation word Each word has a unique address based on the slot number assigned to the module Example Address If you want to configure channel 2 on the module located in slot 4 in the SLC chassis your address would be 0 4 2 Slot File type Wi 0 4 2 ZN Element Word Delimiter Delimiter Word Chapter 4 Channel Configuration Data and Status gives you detailed bit information about the data content of the configuration word Channel Filter Frequency Selection Chapter 3 Things To Consider Before Using Your Module 25 Input Image Data Words and Status Words Eight words of the SLC processor s input image table are reserved for the module Input image words are multiplexed since each channel has one data word and one status word The corresponding configuration word selects whether the channel status or channel data is in the input image word Status bits for a particular channel reflect the configuration settings that you entered into the configuration output image word for that channel To receive valid status the channel must be enabled and the module must have stored a valid configuration word for that channel Each input image word has a unique address based on the slot number assigned to the module Example Address To obtain the status data word of channel 2 input word 2 of the module located in slot 4 in the SLC chassis use address 1 4 2 Slot a NE Element Word Delimiter Delimit
62. bit 0 if the channel is to be enabled Place a zero in bit 0 if the channel is to be disabled Determine the input device type thermocouple RTD resistance mV V or mA for a channel and enter its respective 5 digit binary code in bit field 1 5 of the channel configuration word Remember that only channels 4 7 support the RTD and resistance options Make sure that the shunts are set accordingly for the input types specified Select a data format for the data word value Your selection determines how the analog input value from the A D converter will be expressed in the data word Enter your 2 digit binary code in bit field 6 7 of the channel configuration word Not all data formats apply to all 10 Chapter 4 Channel Configuration Data and Status 35 input types Check table 11 to make sure you selected a valid combination Determine the desired state for the channel data word if an open circuit condition is enabled and detected for that channel Enter the 2 digit binary code in bit field 8 9 of the channel configuration word Not all input types support open circuit detection Review the Open Circuit State description on page 43 to verify applicability If the channel is configured for thermocouple inputs RTD or the CJC sensor determine if you want the channel data word to read in degrees Fahrenheit or degrees Celsius and enter a one or a zero in bit 10 of the configuration word Ifthe channel is configured f
63. can be supplied to meet special tolerances that are equal to approximately one half the standard tolerances given above Type K thermocouple materials are normally supplied to meet the tolerances specified for temperatures above 0 C However the same materials may not satisfy the tolerances specified for the 200 C to 0 C range If materials are required to meet the tolerances below 0 C this should be specified when they are purchased The suggested upper temperature limit of 1260 C given in the ASTM standard 7 for protected type K thermocouples applies to AWG 8 T Type Thermocouples AppendixB Thermocouple Descriptions 95 3 25mm wire It decreases to 1090 C for AWG 14 1 63mm 980 C for AWG 20 0 81mm 870 for AWG 24 or 28 0 51mm or 0 33mm and 760 C for AWG 30 0 25mm These temperature limits apply to thermocouples used in conventional closed end protecting tubes and they are intended only as a rough guide to the user They do not apply to thermocouples having compacted mineral oxide insulation Copper Versus Copper Nickel Alloy Thermocouples This type is one of the oldest and most popular thermocouples for determining temperatures within the range from about 370 C down to the triple point of neon 248 5939 C its positive thermoelement TP is typically copper of high electrical conductivity and low oxygen content that conforms to ASTM Specification B3 for soft or annealed bare copper wire Such material is about
64. ciliana beet 36 Channel Data Word Resol 42 Channel t innne niin e ERR 45 Channel Status Checking 45 Chapter 5 51 Dynamic Programming a cri 53 Verifying Channel Configuration Changes ssesrevesvrvervrvervenrrvenervesvevesvrnersenesnene 54 Interfacing to the PID Instruction 56 Monitoring Channel Status Bits oc repetere rider ere dei dere conca cn 57 Chapter 6 Module and Channel Diagnose 63 LED 1 64 Interpreting 1 0 Error 600108 22 20 e e EEEE EErEE aeei 66 Verifying With Test Instrumentation 7 67 Chapter 7 Preventive M nen es 69 Safety 0010 ER E ERa 69 Appendix A Module Specifications Electrical Specifications mi iene ern e a EE E N 73 74 Environmental S 0601110010 74 Input 661116 80107 74 Appendix B Thermocouple Descriptions ccccsecseeseseeteteeteteeeeeeeeeeceerenees 91 J Type Thermocouples ii A 91 K Wy pe 0 93 T Type Thermocouples unico iii 95 E 600 E eSEE IREE ESER EErEE Ee 97 R Type Thermocouples mmm id 99 S Type Ih rmocouples EE 100 B Type 00 102 N Type Thermocouples cualidad 103 IT 106 Figures Tables Preface Appendix C Using Grounded Junction Ungrounded Junction and Exposed Junction Thermocouples Thermocouples Types scars cseerdiccieiancrhaesciiaescniananinianninein 10 aa a Getting Technical Assistance Declaration of ic Figure 2 1 Module insertion into a rac
65. d was calibrated at 25 C Input Max Error Type 25 C 50mV 20 uV 100mV 30 uV 0 5V 0 3 mV 2 0V 1 0mV 0to 5V 2 5mV 1to 5V 2 5mV 0 to 10V 5 0 mV 10V 5 0 mV 4 to 20mA 40 uA 0 to 20mA 40 uA The following table provides the maximum error for each voltage or current input type when the module is operating at 0 C to 60 C and was calibrated at that temperature Input Max Error Type 0 C to 60 C 50mV 30 uV 100mV 50 UV 0 5V 0 5mV 2 0V 1 5mV 0 to 5V 4 0mV 1to 5V 4 0 mV 0 to 10V 8 0 mV 10V 8 0 mV 4 to 20mA 80 uA 0 to 20mA 80 uA 90 SLC 500 Universal Analog Input Module J Type Thermocouples Appendix B Thermocouple Descriptions The following information was extracted from the NIST Monograph 175 issued in January 1990 which supersedes the IPTS 68 Monograph 125 issued in March 1974 NIST Monograph 175 is provided by the United States Department of Commerce National Institute of Standards and Technology International Temperature Scale of 1990 The ITS 90 1 3 is realized maintained and disseminated by NIST to provide a standard scale of temperature for use in science and industry in the United States This scale was adopted by the International Committee of Weights and Measures CIPM at its meeting in September 1989 and it became the official international temperature scale on January 1 1990 The ITS 90 supersedes the IPTS 68 75 2 and the 1976 Provisional 0 5 K to
66. e Journal of Testing and Evaluation 4 1 42 56 1976 44 Burley N A Powell R L Burns G W Scroger M G The nicrosil versus nisil thermocouple properties and thermoelectric reference data Natl Bur Stand U S Monogr 161 1978 April 167p 45 Burley N A Jones T P Practical performance of nicrosil nisil thermocouples Temperature Measurement 1975 Billing B F Quinn T J ed London and Bristol Institute of Physics 1975 172 180 110 SLC 500 Universal Analog Input Module 46 Burley N A Hess R M Howie C F Nicrosil and nisil new nickel based thermocouple alloys of ultra high thermoelectric stability High Temperatures High Pressures 12 403 410 1980 47 Burley N A Cocking J L Burns G W Scroger M G The nicrosil versus nisil thermocouple the influence of magnesium on the thermoelectric stability and oxidation resistance of the alloys Temperature Its Measurement and Control in Science and Industry Vol 5 Schooley J F ed New York American Institute of Physics 1982 1129 1145 48 Wang T P Starr C D Nicrosil nisil thermocouples in production furnaces in the 538C 1000F to 1177C 2150F range ISA Transactions 18 4 83 99 1979 49 Wang T P Starr C D Oxidation resistance and stability of nicrosil nisil in air and in reducing atmospheres Temperature Its Measurement and Control in Science and Industry Vol 5 Schooley J F ed New
67. e Type S Example Deviations Degrees C Deviation Ch 2 Delta 25C 4 Ch 2 Delta OC e Ch 2 Delta 60C 0 200 400 600 800 1000 1200 Degrees CTC Input Appendix A Module Specifications 81 0 5 Thermocouple Type B Example Deviations viation o al Degrees C De a al 500 700 900 1100 1300 1500 1700 Degrees CTC Input 1900 Ch 2 Delta 25C Ch 2 Delta OC 4 e Ch 2 Delta 60C Degrees C Deviation Thermocouple Type N Example Deviations 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 Degrees C TC Input Ch 2 Delta 25C 4 Ch 2 Delta OC Ch 2 Delta 60C 82 SLC 500 Universal Analog Input Module Thermocouple C Type Example Variations Ch 2 Delta 25C 4 Ch 2 Delta OC e CH 2 Delta 60C Degrees C Variation 0 463 926 1389 1852 2315 Degrees C TC Input RTD and Resistance The following table provides the maximum error for each RTD and resistance type when the 10 Hz 50 Hz and 60 Hz filters are used and the module is operating at 25 C and was calibrated at 25 C Errors due to lead wire resistance mismatches are not included Input Max Error Type 25 C 100Q Pt385 1 0 C 2000 Pt385 0 7 C 5000 Pt 385 0 6 C 10000 Pt385 0 5 C 1000 Pt3916 0 9 C 2000 Pt391
68. e are a few shunts on the board that allow the user to define input paths properly which are imperative for the configuration control to allow proper utilization of the module 1 through JP8 supports the current input mode options of each of the inputs channels 0 through 7 respectively In order to define channels 4 through 7 JP9 and JP10 must be configured properly JP11 is used at the factory and should not be modified JP12 indicates whether or not RTD or resistance inputs are to be used in the configuration The module is shipped with all current input shunts in place and the remaining shunts installed for non RTD or resistance inputs The shunts are to be modified prior to installation of the module Proper precautions for electrostatic handling should be followed Small needlenose pliers may be used to configure the shunts if needed ATTENTION Never touch the module without being properly strapped and connected to ground Electrostatic damage may result JP1 JP2 JP3 JP4 JP5 JP6 JP7 and JP8 Setup Current Input Non Current Input JP11 Setup Chapter 2 Installing And Wiring Your Module 11 The following diagram shows the module outline defining the placement of the various shunts looking at the primary side of the board with the terminal block pointing up A brief description of each follows Terminal Block Header ses ez al sea Loes Laes Laer ue There are eight shunts corresponding
69. e example shows how you could monitor the open circuit error bits of each channel and set an alarm in the processor if one of the inputs opens An open circuit error can occur if one of the input signal wires gets cut or disconnected from the terminal block or if the CJC sensors are not installed or are damaged Important Ifa CJC input is not installed or is damaged all thermocouple alarms are set and their respective channel LEDs blink SLC 500 Universal Analog Input Module Figure 5 10 Monitoring channel status bits example Program Listing Rung 2 0 First Pass Bit Initialize NI8u Channel 0 s l COP d E COPY FILE gt 15 Sourc N10 0 Dest 0 53 0 Length 8 Rung 2 1 Channel 0 Channel 0 Channel 0 Enable Open Alarm 3 40 T 3 0 032 0 1 1 J gt E 0 12 O Rung 2 2 Channel 1 Channel 1 Channel 1 Enable Open Alarm 11341 41 OF 2 6 i 1 LP 0 12 1 Rung 2 3 Channel 2 Channel 2 Channel 2 Enable Open Alarm 1 32 2 0 2 0 I E R 0 2 2 Rung 2 4 Channel 3 Channel 3 Channel 3 Enable Open Alarm E233 T 3 3 0 22 10 1 d E O 12 Rung 2 5 Channel 4 Channel 4 Channel 4 Enable Open Alarm I 3 4 I 3 4 052 60 1 1 J E 0 12 4 Rung 2 6 Channel 5 Channel 5 Channel 5 Enable Open Alarm 1 3 5 Tio 0 20 1 J P 0 12 5 Rung 2 7 Channel 6 Channel 6 Channel 6 Enable Open Alarm 1 3 6 T 3 6 0 20 1 1 E
70. ected When an input channel is disabled its data word is reset 0 Module Input Image Data Status Words Channel Status Checking Channel 0 Channel Data Status Word SS S Channel 1 Channel Data Status Word Channel 2 Channel Data Status Word Channel 3 Channel Data Status Word Channel 4 Channel Data Status Word Channel 5 Channel Data Status Word fl ie le Al fl a 1 Channel 6 Channel Data Status Word Channel 7 Channel Data Status Word 1 1 1 1 1 1 1 I L 1 1 1 1 1 1 1 1 The input image of the module is 8 words Since there are 8 channels with a data word and a status word for each channel the input image information is multiplexed The information in the input image is the channel data word if bit 15 of the channel s configuration word is 1 The information in the input image is the channel status word if bit 15 of the channel s configuration word is 0 You can use the information provided in the status word to determine if the input configuration data for any channel is valid per your configuration in O e 0 through O e 7 46 SLC 500 Universal Analog Input Module The channel status can be analyzed bit by bit In addition to providing information about an enabled or disabled channel each bit s status 0 or 1 tells you how the input data fr
71. ed channel detects an over range condition for the channel data An over range condition exists when the input value is equal to or above the specified upper limit of the particular sensor connected to that channel Channel Error Bit 15 This bit is set 1 whenever a configured channel detects an error in the configuration word or an error has occurred while acquiring the ADC data value If during the auto calibration process the module detects an out of range condition for the filter frequency selected for the channel the channel error bit will be set An out of range condition occurring during auto calibration would be the result of an overly noisy environment whereby the module cannot maintain accuracy specifications thus flagging an error The error bit is cleared when the error condition is resolved The channel data word is still updated during a period of auto calibration filter frequency tolerance errors but accuracy may be degraded 50 SLC 500 Universal Analog Input Module Initial Programming Chapter 5 Programming Examples Earlier chapters explained how the configuration word defines the way a channel operates This chapter shows the programming required to enter the configuration word into the processor memory It also provides you with segments of ladder logic specific to unique situations that might apply to your programming requirements The example segments include initial programming of the configu
72. er Word Chapter 4 Channel Configuration Data and Status gives you detailed bit information about the content of the data word and the status word The universal module uses a digital filter that provides high frequency noise rejection for the input signals The digital filter is programmable allowing you to select from four filter frequencies for each channel The digital filter provides the highest noise rejection at the selected filter frequency The graphs to follow show the input channel frequency response for each filter frequency selection Selecting a low value i e 10 Hz for the channel filter frequency provides the best noise rejection for a channel but it also increases the channel update time Selecting a high value for the channel filter frequency provides lower noise rejection but decreases the channel update time The following table shows the available filter frequencies cut off frequency step response and ADC effective resolution for each filter frequency SLC 500 Universal Analog Input Module Table 3 1 Cut off frequency step response time and effective resolution based on filter frequency Filter Cut Off Step ADC Effective Frequency Frequency Response Resolution 10 Hz 2 62 Hz 300 ms 20 5 50 Hz 13 1 Hz 60 ms 19 0 60 Hz 15 72 Hz 50 ms 19 0 250 Hz 65 5 Hz 12 ms 15 5 The step response is calculated by a 3 x 1 filter frequency settling time Channel Cut Off Frequency The channel filter
73. erted to nickel and zinc Because of the high thermal conductivity of type TP thermoelements special care should be exercised when using the thermocouples to ensure that the measuring and reference junctions assume the desired temperatures ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for type T commercial thermocouples be 1 C or 0 75 whichever is greater between 0 C and 350 C and 1 C or 1 5 whichever is greater between 200 C and 0 C Type T thermocouples can also be supplied to meet special tolerances which are equal to approximately one half the standard tolerances given above Type T thermocouple materials are normally E Type Thermocouples AppendixB Thermocouple Descriptions 97 supplied to meet the tolerances specified for temperatures above 0 C However the same materials may not satisfy the tolerances specified for the 200 C to 0 C range If materials are required to meet the tolerances below 0 C this should be specified when they are purchased The suggested upper temperature limit of 370 C given in the ASTM standard 7 for protected type T thermocouples applies to AWG 14 1 63mm wire It decreases to 260 C for AWG 20 0 81mm 200 C for AWG 24 or 28 0 51mm or 0 33mm and 150 C for AWG 30 0 25mm These temperature limits apply to thermocouples used in conventional closed end protecting tubes and they are intended only
74. example if channel one is configured as a thermocouple type when the CJC breaks in an open circuit condition if open circuit detection is disabled the data word will remain unchanged If the circuit selection is set at minimum the data word will be set to the low scale value for the range and format Select Temperature Units Bit 10 The temperature units bit lets you select temperature engineering units for thermocouple RTD and CJC input types Units are either degrees Celsius C or degrees Fahrenheit F This bit field is only active for thermocouple RTD and CJC input types It is ignored when millivolt or current inputs types are selected Select Channel Filter Frequency Bits 11 and 12 The channel filter frequency bit field lets you select one of four filters available for a channel The filter frequency affects the channel update time and noise rejection characteristics A smaller filter frequency increases the channel update time but also increases the noise rejection and channel resolution A larger filter frequency decreases the noise rejection but also decreases the channel update time and channel resolution 250 Hz setting provides minimal noise filtering 60 Hz setting provides 60 Hz AC line noise filtering 50 Hzsetting provides 50 Hz AC line noise filtering e 10 Hz setting provides both 50 Hz and 60 Hz AC line noise filtering When a CJC input type is selected this field is ignored To maximize the
75. ferenced herein The information in this owner s guide is subject to change without notice Limited Warranty Spectrum Controls warrants that its products are free from defects in material and workmanship under normal use and service as described in Spectrum Controls literature covering this product for a period of 1 year The obligations of Spectrum Controls under this warranty are limited to replacing or repairing at its option at its factory or facility any product which shall in the applicable period after shipment be returned to the Spectrum Controls facility transportation charges prepaid and which after examination is determined to the satisfaction of Spectrum Controls to be thus defective This warranty shall not apply to any such equipment which shall have been repaired or altered except by Spectrum Controls or which shall have been subject to misuse neglect or accident In no case shall the liability of Spectrum Controls exceed the purchase price The aforementioned provisions do not extend the original warranty period of any product which has either been repaired or replaced by Spectrum Controls Who Should Use This Guide What This Guide Covers Related Allen Bradley Documents Preface Read this preface to familiarize yourself with the rest of the owner s guide This preface covers e who should use this guide what this guide covers related Allen Bradley documents terms amp abbreviati
76. ffer the best overall combination of desirable properties Type T thermocouples are recommended by the ASTM 5 for use in the temperature range from 200 C to 370 C in vacuum or in oxidizing reducing or inert atmospheres The suggested upper temperature limit for continuous service of protected type T thermocouples is set at 370 C for AWG 14 1 63mm thermoelements since type TP thermoelements oxidize rapidly above this temperature However the thermoelectric properties of type TP thermoelements are apparently not grossly affected by oxidation since negligible changes in the thermoelectric voltage were observed at NBS 10 for AWG 12 18 and 22 type TP thermoelements during 30 hours of heating in air at 500 C At this temperature the type TN thermoelements have good resistance to oxidation and exhibit only small voltage changes heated in air for long periods of time as shown by the studies of Dahl 11 Higher operating temperatures up to at least 800 C are possible in inert atmospheres where the deterioration of the type TP thermoelement is no longer a problem The use of type T thermocouples in hydrogen atmospheres at temperatures above about 370 C is not recommended since type TP thermoelements may become brittle Type T thermocouples are not well suited for use in nuclear environments since both thermoelements are subject to significant changes in composition under thermal neutron irradiation The copper in the thermoelements is conv
77. frequency selection determines a channel s cut off frequency also called the 3 dB frequency The cut off frequency is defined as the point on the input channel frequency response curve where frequency components of the input signal are passed with 3 dB of attenuation All frequency components at or below the cut off frequency are passed by the digital filter with less than 3 dB of attenuation All frequency components above the cut off frequency are increasingly attenuated as shown in the graphs below The cut off frequency for each input channel is defined by its filter frequency selection The table above shows the input channel cut off frequency for each filter frequency Choose a filter frequency so that your fastest changing signal is below that of the filter s cut off frequency The cut off frequency should not be confused with update time The cut off frequency relates how the digital filter attenuates frequency components of the input signal The update time defines the rate at which an input channel is scanned and its channel data word updated Chapter 3 Things To Consider Before Using Your Module 27 Figure 3 2 Signal attenuation with 10 Hz input filter 308 Y Amplitude in dB 100 120 140 160 180 200 20 40 60 80 0 M 2 62 Hz 10 20 30 40 50 60 Hz Signal Frequency Figure 3 3 Signal attenuation with 50 Hz input filter 3d Y Amplitude in dB 20 40 60 80 100
78. ges have taken effect Example Execute a dynamic configuration change to channel 2 of the universal module located in slot 3 of a 1746 chassis and set an internal data valid bit when the new configuration has taken effect In this example the input image of the channel is selected to contain the channel status word Chapter Ladder Program Examples 55 Figure 5 6 Programming for configuration changes example Rung 2 0 Set up all eight channels SEL r COP COPY FILE 15 Source N10 0 Dest 0 3 0 Length 8 Rung 2 1 Set channel 2 to CJC I 1 0 B3 MOV OSR MOVE 0 Source N10 8 Dest 0 3 2 Rung 2 2 Set channel 2 back to 10V 0 B3 MOV d i OSR MOVE 0 1 Source N10 2 Dest 03 2 Check that the configuration written to channel two is being echoed back in channel two s status word Rung 2 3 m EQU EQUAL B3 Source A 1 3 2 3 Source B 0 3 2 Rung 2 4 I END I Figure 5 7 Data table for configuration changes Data Table address 15 data 0 address 15 data O N10 0 1000 G011 0101 0011 N10 8 0009 0000 OIL TILL N10 1 1000 0011 0101 0011 2 1000 0011 0101 1 N10 3 1000 0011 0101 1 N10 4 1000 0011 0101 0011 N10 5 1000 0011 0101 0011 N10 6 1000 0011 0101 0011 N10 7 1000 0011 0101 0011 56 SLC 500 Universal Analog Input Module Interfacing to the PID Instruction The universal module was designed to interface directly to
79. h filter frequencies 100 dB at 50 Hz 100 dB at 60 Hz 100 dB at 50 60 Hz 2 6 Hz at 10 Hz filter frequency 13 1 Hz at 50 Hz filter frequency 15 72 Hz at 60 Hz filter frequency 65 5 Hz at 250 Hz filter frequency Module autocalibrates at power up and approximately every two minutes afterwards 14 5 VDC continuous 250W pulsed for 1 msec 28 mA continuous 40 mA 1mS pulsed 10 duty cycle maximum 500 VDC continuous between inputs and chassis ground and between inputs and backplane 12 5 VDC continuous between channels of TC V i 0 VDC between channels of RTD See page 28 for detailed explanation of auto calibration 74 SLC 500 Universal Analog Input Module Physical Specifications Input Specifications LED Indicators Module ID Code Recommended Cable for thermocouple inputs for mV V or mA inputs for RTD inputs Maximum Wire Size 9 green status indicators one for each of 8 channels and one for module status 3500 Shielded twisted pair thermocouple extension wire Belden 8761 or equivalent shielded Belden 9501 9533 83503 One 16 AWG wire or two 22 AWG wires per terminal O Refer to the thermocouple manufacturer for the correct extension wire Refer to the RTD manufacturer and Chapter 1 of this user s manual Operating Temperature Storage Temperature Relative Humidity Certification Hazardous Environment Classification EMC Type of Input Selectable 0 C to 60 C 32
80. h a small fraction of the total production of commercial iron wire that the producers do not control the chemical composition to maintain constant thermoelectric properties Instead instrument companies and thermocouple fabricators select material most suitable for 92 SLC 500 Universal Analog Input Module the thermocouple usage The total and specific types of impurities that occur in commercial iron change with time location of primary ores and methods of smelting Many unusual lots have been selected in the past for example spools of industrial iron wire and even scrapped rails from an elevated train line At present iron wire that most closely fits these tables has about 0 25 percent manganese and 0 12 percent copper plus other minor impurities The negative thermoelement for type J thermocouples is a copper nickel alloy known ambiguously as constantan The word constantan has commonly referred to copper nickel alloys containing anywhere from 45 to 60 percent copper plus minor impurities of carbon cobalt iron and manganese Constantan for type J thermocouples usually contains about 55 percent copper 45 percent nickel and a small but thermoelectrically significant amount of cobalt iron and manganese about 0 1 percent or more It should be emphasized that type JN thermoelements are NOT generally interchangeable with type TN or EN thermoelements although they are all referred to as constantan In order to provide so
81. hings to consider Indicator Lights When the module status LED on your module is illuminated your module is receiving power Activating Devices When Troubleshooting Never reach into a machine to activate a device the machine may move unexpectedly Use a wooden stick 70 SLC 500 Universal Analog Input Module Standing Clear Of Machinery When troubleshooting a problem with any SLC 500 system have all personnel remain clear of machinery The problem may be intermittent and the machine may move unexpectedly Have someone ready to operate an emergency stop switch CAUTION POSSIBLE EQUIPMENT OPERATION Never reach into a machine to actuate a switch Also remove all electrical power at the main power disconnect switches before checking electrical connections or inputs outputs causing machine motion Failure to observe these precautions can cause personal injury or equipment damage Safety Circuits Circuits installed on machinery for safety reasons like over travel limit switches stop push buttons and interlocks should always be hard wired to the master control relay These circuits should also be wired in series so that when any one circuit opens the master control relay is de energized thereby removing power Never modify these circuits to defeat their function Serious injury or equipment damage may result WARNING EXPLOSION HAZARD SUBSTITUTION OF COMPONENTS MAY IMPAIR SUITABILITY FOR CLAS
82. hrough 7 may be configured for current voltage thermocouple RTD or resistance inputs The definition of the bits in the configuration words are described in the ch arts below 36 SLC 500 Universal Analog Input Module Table 4 1 Channel Configuration Word O e 3 0 Channel 3 0 1514 13 12 11 10 9 8 7 6 5 4 3 210 Channel Channel disable 0 Enable Channel enable il 4 to 20 mA 0 to 20 mA 0 05 V 0 10 V E 0 50 V 2 0 V 0to5V Input 1 to 5V Type 0 to 10V 10V Thermocouple Type J Thermocouple Type K Theromcouple Type T Thermocouple Type E Thermocouple Type R Thermocouple Type S Thermocouple Type B Thermocouple Type N 5 re be e RHEE HOC 0 0 OC OC OC 5 0 5 aaa oooooooo ro oorroor oorroor oo0o ORFF ROR OH 0 OR OR or OF or o Invalid Invalid Invalid Invalid Thermocouple Type C CIC Engineering Units x1 0 0 Data Engineering Units x10 0 1 Format Scaled for PID 1 0 Proportional counts L Zero on open circuit 0 0 Open Max on open circuit 0 1 Circuit Min on open circuit 1 0 Disabled 1 1 Temperature Degrees C 0 Units Degrees F 1 Channel 10 Hz input filter 0 0 filter 50 Hz input filter 0 1 freq 60 Hz input filter 1 0 250 Hz input filter 1 1 Unused 0 Auto cal Enabled 0 Disabled 1 Input Image Status word 0 Type Data word 1 Channel 7 4 Channel Enable Channel disable Channel enable 4to 20 mA 0 to 20 mA 0 05 V 0 10 V 0 50
83. iety of voltage and current devices with an output of 50 5100 mV 500mV 2V 0 5V 1 5V 0 10V 10V 0 20mA and 4 20mA To minimize interference from radiated electrical noise we recommend twisted pair and highly shielded cables such as the following Table 1 7 Recommendations to minimize interference from radiated electrical noise For This Type of Device We Recommend This Cable or equivalent Thermocouple Type J EIL Corp J20 5 502 Thermocouple Type K EIL Corp K20 5 510 Thermocouple Type T EIL Corp T20 5 502 Other Thermocouple Types consult with EIL Corp or other manufacturers mV V mA devices Belden 8761 shielded twisted pair SLC 500 Universal Analog Input Module Compatibility with RTD and Resistance devices and cables The module is compatible 100Q Platinum 385 200Q Platinum 385 55Q Platinum 385 1000Q Platinum 385 100Q Platinum 3916 200Q Platinum 3916 500Q Platinum 3916 10002 Platinum 3916 10Q Copper 426 120Q Nickel 618 and 1200 Nickel 672 RTD types and 30000 resistance inputs and 3 possible wire types 2 wire 3 wire or 4 wire Each RTD input individually supports four input pins on the terminal block one excitation current source EXC one excitation current drain EXC one sense positive CH and one sense negative CH Only those pins are connected that are required by the selected RTD or resistance wire type For 2 3 or 4 wire configurations the module can sup
84. ificant impurities of elements such as palladium iridium iron and silicon 38 Studies by Ehringer 39 Walker et al 25 26 and Glawe and Szaniszlo 24 have demonstrated that thermocouples in which both legs are platinum rhodium alloys are suitable for reliable temperature measurements at high temperatures Such thermocouples have been shown to offer the following distinct advantages over types R and S thermocouples at high temperatures 1 improved stability 2 increased mechanical strength and 3 higher operating temperatures The research by Burns and Gallagher 38 indicated that the 30 6 thermocouple can be used intermittently for several hours up to 1790 C and continuously for several hundred hours at temperatures up to about 1700 C with only small changes in calibration The maximum temperature limit for the thermocouple is governed primarily by the melting point of the Pt 6 rhodium thermoelement which is estimated to be about 1820 C by Acken 40 The thermocouple is most reliable when used in a clean N Type Thermocouples AppendixB Thermocouple Descriptions 103 oxidizing atmosphere air but also has been used successfully in neutral atmospheres or vacuum by Walker et al 25 26 Hendricks and McElroy 41 and Glawe and Szaniszlo 24 The stability of the thermocouple at high temperatures has been shown by Walker et al 25 26 to depend primarily on the quality of the materials used for protecting and in
85. ight hand corner below JP11 The module will either support zero RTD or resistance inputs or four RTD or resistance inputs in channels 4 through 7 To properly configure JP9 and JP10 for RTD or resistance set the shunts across pins 2 and 3 of the four pin headers JP12 also needs to have pins 2 and 3 connected when RTD or resistance are to be used as shown below If RTD and resistance inputs are not used and channels 4 through 7 are to be defined as thermocouple inputs current inputs millivolt or voltage inputs jumper pins and 2 together jumper pins 3 and 4 together of JP9 and JP10 as defined below JP12 also needs to have pins and 2 connected when RTD and resistance inputs are not in use Selecting A Rack Slot Module Installation and Removal Chapter 2 Installing And Wiring Your Module 13 Two factors determine where you should install your module in the rack ambient temperature and electrical noise When selecting a slot for your module try to position your module e ina rack close to the bottom of the enclosure where the air is cooler away from modules that generate significant heat such as 32 point input output modules e in a slot away from ac or high voltage de modules hard contact switches relays and ac motor drives away from the rack power supply if using a modular system Remember that in a modular system the processor always occupies the first slot of the rack When installing the modu
86. ile N10 Figure 5 2 Data table for initial programming address 15 data 0 address 15 data 0 N10 0 0000 0010 0 0011 N10 3 0000 0010 0010 0011 N10 4 0000 0010 0010 0011 N10 5 0000 0010 0010 0011 N10 6 0000 0010 0010 0011 N10 7 0000 0010 0010 0011 Press a key or enter value N10 3 0 1 offline no forces binary data decimal addr File EXMPL CHANGE SPECIFY NEXT PREV RADIX ADDRESS FILE FILE F1 F5 F7 F8 3 Program a rung in your ladder logic to copy the contents of integer file N10 to the eight consecutive output words of the universal module beginning with 0 3 0 Figure 5 3 Initial programming example First Pass Bit Initialize Module sl COP gt f COPY FILE 15 Source N10 0 Length 8 Dest 0 3 0 On power up bit S 1 15 is set for the first program scan and integer file N10 is sent to the NI8u channel configuration words Dynamic Programming Chapter Ladder Program Examples 53 The following example explains how to change data in the channel configuration word when the channel is currently enabled Example Execute a dynamic configuration change to channel 2 of the universal module located in slot 3 of a 1746 chassis Change from monitoring a bipolar 10 V signal to monitoring the CJC sensors mounted on the terminal block This gives a good indication of what the temperature is inside the control cabinet Finally set channel 2 back to the bipolar 10 V
87. in an international collaborative effort involving eight national laboratories The results of this international collaboration were reported by Burns et al 28 The new function was used to compute the reference table given in this monograph Research 27 demonstrated that type S thermocouples can be used from 50 C to the platinum melting point temperature They may be used intermittently at temperatures up to the platinum melting point and continuously up to about 1300 C with only small changes in their calibrations The ultimate useful life of the thermocouples when used at such elevated temperatures is governed primarily by physical problems of impurity diffusion and grain growth which lead to mechanical failure The thermocouple is most reliable when used in a clean oxidizing atmosphere air but may be used also in inert gaseous atmospheres or in a vacuum for AppendixB Thermocouple Descriptions 101 short periods of time However type B thermocouples are generally more suitable for such applications above 1200 C Type S thermocouples should not be used in reducing atmospheres nor in those containing metallic vapor such as lead or zinc nonmetallic vapors such as arsenic phosphorus or sulfur or easily reduced oxides unless they are suitably protected with nonmetallic protecting tubes Also they should never be inserted directly into a metallic protection tube for use at high temperatures The stability of type S thermocouples
88. in type S thermocouples when used to 1064C High Temperatures High Pressures 12 33 45 1980 35 Rhys D W Taimsalu P Effect of alloying additions on the thermoelectric properties of platinum Engelhard Tech Bull 10 41 47 1969 36 Cochrane J Relationship of chemical composition to the electrical properties of platinum Engelhard Tech Bull 11 58 71 1969 Also in Temperature Its Measurement and Control in Science and Industry Vol 4 Plumb H H ed Pittsburgh Instrument Society of America 1972 1619 1632 37 Aliotta J Effects of impurities on the thermoelectric properties of platinum Inst and Control Systems 106 107 March 1972 38 Burns G W Gallagher J S Reference tables for the Pt 30 percent Rh versus Pt 6 percent Rh thermocouple J Res Natl Bur Stand U S 70C 89 125 1966 39 Ehringer H Uber die lebensdauer von PtRh thermoelementen Metall 8 596 598 1954 40 Acken J S Some properties of platinum rhodium alloys J Res Natl Bur Stand U S 12 249 RP650 1934 41 Hendricks J W McElroy D L High temperature high vacuum thermocouple drift tests Environmental Quarterly 34 38 March 1967 42 Zysk E D Platinum metal thermocouples Temperature Its Measurement and Control in Science and Industry Vol 3 Herzfeld C M ed New York Reinhold Publishing Corp 1962 Part 2 pp 135 156 43 Starr C D Wang T P A new stable nickel base thermocoupl
89. izing and reducing atmospheres unless suitably protected with protecting tubes They also should not be used in vacuum at high temperatures for extended times because the chromium in the positive thermoelement a nickel chromium alloy vaporizes out of solution and alters the calibration In addition their use in atmospheres that promote green rot corrosion 9 of the positive thermoelement should be avoided Such corrosion results from the preferential oxidation of chromium in atmospheres with low but not negligible oxygen content and can lead to a large decrease in the thermoelectric voltage of the thermocouple with time The effect is most serious at temperatures between 800 C and 1050 C Both thermoelements of type K thermocouples are reasonably stable thermoelectrically under neutron irradiation since the resulting changes in their chemical compositions due to transmutation are small The KN thermoelements are somewhat less stable than the KP thermoelements in that they experience a small increase in the iron content accompanied by a slight decrease in the manganese and cobalt contents ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for type K commercial thermocouples be 2 2 C or 0 75 whichever is greater between 0 C and 1250 C and 2 2 C or 2 whichever is greater between 200 C and 0 C In the 0 C to 1250 C range type K thermocouples
90. k Using a screwdriver or needle nose pliers carefully unscrew and then pry the terminal block loose When removing or installing the terminal block be careful not to damage the CJC sensors Chapter 2 Installing And Wiring Your Module 15 Terminal block diagram with CJC sensors Figure 2 2 CJC Sensors l CHO CJCA CHO CJCA Shield 0 1 CH2 A CH1 CH2 CH1 SHIELD 2 3 EXC4 CH3 CH4 CH3 CH4 EXC6 EXC4 TT LET CH6 Shield 4 5 CEI EDT cHe EXC5 LL CLI Exce CH5 CT I SHIELD 6 7 CH5 CJ EXC7 EXC5 I TH CH7 CJCB CH7 CJCB EXC7 CJC Sensors CAUTION POSSIBLE EQUIPMENT OPERATION Before wiring your module always disconnect power from the SLC 500 system and from any other source to the module Failure to observe this precaution can cause unintended equipment operation and damage Wiring Your Module Follow these guidelines to wire your input signal cables e Power input and output I O wiring must be in accordance with Class 1 Division 2 wiring methods Article 501 4 b of the National Electrical Code NFPA 70 and in accordance with the authority having jurisdiction Peripheral equipment must be suitable for the location in which it is used Route the field wiring away from any othe
91. k Ne Figure 2 2 Terminal block diagram with CJC sensors 00 Figure 2 3 Ferrite EMI suppressor for CE compliance 2 Figure 2 4 Terminal block diagram with input cable oe eee Figure 3 2 Signal attenuation with 10 Hz input filter ee Figure 3 3 Signal attenuation with 50 Hz input filter Figure 3 4 Signal attenuation with 60 Hz input filter oo Figure 3 5 Signal attenuation with 250 Hz input filter co Figure 5 1 Channel configuration coins tala Figure 5 2 Data table for initial programming ee Figure 5 3 Initial programming example Figure 5 4 Dynamic programming example pe Figure 5 5 Data table for dynamic programming Rs Figure 5 6 Programming for configuration changes example Figure 5 7 Data table for configuration changeS ee Figure 5 8 Programming for PID Control Example ppp Figure 5 9 Data table for PID Control AAA Figure 5 10 Monitoring channel status bits example coccion Figure 5 11 Data table for monitoring channel status bits 0 00 Figure 6 1 Troubleshooting 1100 Table 1 1 Thermocouple Temperature Ranges Rs Table 1 2 RTD Temperature Ranges RN Table 1 3 Millivolt Input Ranges 42k Table 1 4 Current Input 7 Table 1 5 Resistance Input Range 3 sapiens Table 1 6 Hardware Features Table 1 7 Recommendations to minimize interference from radiated electrical 0186 Table 1 8 Cable SpecificationSinsssnosisnconnriesonesnninss Table 2 1 Maximum current draw
92. k for short circuited RTD connections Retry Enable channel if channel or the CJC gt Yes Is problem corrected Contact you local distributor or Spectrum Controls Preventive Maintenance Safety Considerations Chapter 7 Maintaining Your Module And Ensuring Safety Read this chapter to familiarize yourself with preventive maintenance safety considerations The National Fire Protection Association NFPA recommends maintenance procedures for electrical equipment Refer to article 70B of the NFPA for general safety related work practices The printed circuit boards of your module must be protected from dirt oil moisture and other airborne contaminants To protect these boards install the SLC 500 system in an enclosure suitable for its operating environment Keep the interior of the enclosure clean and whenever possible keep the enclosure door closed Also regularly inspect the terminal connections for tightness Loose connections may cause a malfunctioning of the SLC system or damage to the components WARNING POSSIBLE LOOSE CONNECTIONS Before inspecting connections always ensure that incoming power is OFF Failure to observe this precaution can cause personal injury and equipment damage Safety is always the most important consideration Actively think about the safety of yourself and others as well as the condition of your equipment The following are some t
93. le To limit overall cable impedance keep input cables as short as possible Locate your I O chassis as near the RTD or thermocouple sensors as your application will permit Tighten screw terminals with care Excessive tightening can strip a screw Follow system grounding and wiring guidelines found in your SLC 500 Installation and Operation Manual The NI8u module supports two three and four wire RTDs or resistance inputs connected individually to the module channels 4 through 7 as shown in the figure below Chapter 2 Installing And Wiring Your Module 17 2 Wire RTD Interconnection EXC4 ADD CH4 JUMPER CH4 EXC4 Shield 4 5 ADD EXC4 JUMPER CH4 CH4 EXC4 Shield 4 5 EXC4 CH4 CH4 EXC4 Shield 4 5 CABLE SHIELD These are 2 wire RTDs which are composed of 2 RTD lead wires RTD and Return 3 wire RTDs which are composed of a Sense and 2 RTD lead wires RTD and Return 4 wire RTDs which are composed of 2 Sense and 2 RTD lead wires RTD and Return In any RTD sensing system it is important that the lead and sense wire resistances are matched as much as possible The lead lengths and their resulting impedances must be matched and kept small to eliminate the introduction of connectivity errors The 4 wire RTDs are the most accurate with 2 wire RTDs being the most inaccurate In 2 wire the lead resistance adds error to the resulting degree reading Wi
94. le in a chassis it is not necessary to remove the terminal blocks from the module However if the terminal blocks are removed use the write on label located on the side of the terminal blocks to identify the module location and type 1746sc Ni8u RACK SLOT 5 D 1746sc RACK SLOT 8 CAUTION POSSIBLE EQUIPMENT OPERATION Before installing orremoving your module always disconnect powerfrom the SLC 500 system and from any other source to the module in other words don t hot swap your module and disconnect any devices wired to the module Failure to observe this precaution can cause unintended equipment operation and damage 14 SLC 500 Universal Analog Input Module To insert your module into the rack follow these steps 1 Align the circuit board of your module with the card guides at the top and bottom of the chassis Figure 2 1 Module insertion into a rack SN a Y NS e 8 gt eege e Wi d S E CES DE TB2 2 Slide your module into the chassis until both top and bottom retaining clips are secure Apply firm even pressure on your module to attach it to its backplane connector Never force your module into the slot Cover all unused slots with the Card Slot Filler Allen Bradley part number 1746 N2 Terminal Block Removal To remove the terminal bloc
95. m oxide and sheathed in Inconel and in stainless steel Their studies showed that the thermoelectric instabilities of such assemblies increase rapidly with temperature above 1000 C It was found also that the smaller the diameter of the sheath the greater the instability Additionally thermocouples sheathed in Inconel showed substantially less instability above 1000 C than those sheathed in stainless steel Bentley and Morgan 52 stressed the importance of using Inconel sheathing with a very low manganese content to achieve the most stable performance The use of special Ni Cr based alloys for sheathing to improve the chemical and physical compatibility with the thermoelements also has been investigated by Burley 54 56 and by Bentley 57 60 Neither thermoelement of a type N thermocouple is extremely sensitive to minor differences in heat treatment provided that the treatment does not violate any of the restrictions mentioned above For most general applications they may be used with the heat treatment routinely given by the wire manufacturer Bentley 61 62 however has reported reversible changes in the Seebeck coefficient of type NP and NN thermoelements when heated at temperatures between 200 C and 1000 C These impose limitations on the accuracy obtainable with type N thermocouples The magnitude of such changes was found to depend on the source of the thermoelements Consequently when the highest accuracy and stability are sought
96. me differentiation in nomenclature type JN is often referred to as SAMA constantan Type J thermocouples are recommended by the ASTM 5 for use in the temperature range from 0 C to 760 C in vacuum oxidizing reducing or inert atmospheres If used for extended times in air above 500 C heavy gage wires are recommended because the oxidation rate is rapid at elevated temperatures Oxidation normally causes a gradual decrease in the thermoelectric voltage of the thermocouple with time Because iron rusts in moist atmospheres and may become brittle type J thermocouples are not recommended for use below 0 C In addition they should not be used unprotected in sulfurous atmospheres above 500 C The positive thermoelement iron is relatively insensitive to composition changes under thermal neutron irradiation but does exhibit a slight increase in manganese content The negative thermoelement a copper nickel alloy is subject to substantial composition changes under thermal neutron irradiation since copper is converted to nickel and zinc Iron undergoes a magnetic transformation near 769 C and an alpha gamma crystal transformation near 910 C 6 Both of these transformations especially the latter seriously affect the thermoelectric properties of iron and therefore of type J thermocouples This behavior and the rapid oxidation rate of iron are the main reasons why iron versus constantan thermocouples are not recommended as a standardized
97. module at the end of the program scan or when commanded by the ladder program After the processor and module determine that the data transfer was made without error the data can be used in your ladder program Chapter 1 Module Overview 5 Module Operation The module s input circuitry consists of eight differential analog inputs multiplexed into an A D converter The A D converter reads the analog input signals and converts them to digital counts The input circuitry also continuously samples the CJC sensors and compensates for temperature changes at the cold junction terminal block The module can be used with remote CJC sensor inputs The sensors must be Analog Devices AD592CN temperature transducers The module will not accept other CJC sensor inputs and thermocouple inputs will not function properly if incorrect CJC sensors are used Module Addressing The module requires eight words each in the SLC processor s input and output image tables Addresses for the module in slot e are as follows 1 6 0 7 thermocouple mV V mA RTD resistance or status data for channels 0 7 respectively O e 0 7 configuration data for channels 0 7 respectively Compatibility with Thermocouple Current and Millivolt Devices amp Cables The module is compatible with the following standard types of thermocouples B E J K N R S T and C and extension wire Refer to appendices B and C for details The module is also compatible with a var
98. n by the module pe Table 3 1 Cut off frequency step response time and effective resolution based on filter frequency Table 3 2 Channel Sampling Time 111424 vii viii SLC 500 Universal Analog Input Modules Table 4 1 Table 4 2 Table 4 3 Table 4 4 Table 4 5 Table 6 1 Table 6 2 Channel Configuration Word 2 6 3 0 36 Channel Configuration Word 2 6 7 4 renerne renerne 37 1746sc NI8u Universal Module Channel Data Word Format 41 1746sc NI8u Thermocouple Module Ne 42 Channel 0 7 Status Word I e 0 through I e 7 Bit Ree 46 Module status LED 64 Module status and Channel status 1 51 64 General Description Chapter 1 Module Overview This chapter describes the universal analog input module and explains how the SLC controller reads thermocouple or millivolt analog input data from the module Read this chapter to familiarize yourself further with your universal analog input module This chapter covers general description and hardware features anoverview of system and module operation block diagram of channel input circuits This module is designed exclusively to mount into Allen Bradley 1746 I O racks for use with Allen Bradley SLC 500 fixed and modular systems The module stores digitally converted thermocouple RTD millivolt mV volt V milliamp mA and CJC temperature analog data in its image table for retrieval by all fixed and modular SLC 500 p
99. n of chromium in atmospheres with low but not negligible oxygen content and can lead to a large decrease in the thermoelectric voltage of the thermocouple with time The effect is most serious at temperatures between 800 C and 1050 C The negative thermoelement a copper nickel alloy is subject to composition changes under thermal neutron irradiation since the copper is converted to nickel and zinc Neither thermoelement of type E thermocouples is very sensitive to minor changes in composition or impurity level because both are already heavily alloyed Similarly they are also not extremely sensitive to minor differences in heat treatment provided that the treatment does not violate any of the restrictions mentioned above For most general applications they may be used with the heat treatment given by the wire manufacturers However when the highest accuracy is sought additional preparatory heat treatments may be desirable in order to enhance their performance Details on this and other phases of the use and behavior of type KP thermoelements EP is the same as KP are given in publications by Pots and McElroy 14 by Burley and Ackland 15 by Burley 16 by Wang and Starr 17 18 by Bentley 19 and by Kollie et al 20 ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for type E commercial thermocouples be 1 7 C or 0 5 whichever is greater between 0 C
100. nd potentiometers Long runs greater than 100 feet or high humidity levels 3 24 AWG tinned copper 7x32 Beldfoil aluminum polyester shield w copper drain wire Teflon Red teflon NEC Art 800 Type CMP 200 C Chapter 1 Module Overview Block Diagram Multiplexers CJCA Sensor DC Voltage Analog Input Thermocouple i EXC 6 Input CH6 0 20 mA Current Input RTD or resistance Input 9 Filter Value Converter User Selected Filter Frequency SLC 500 Universal Analog Input Module Chapter 2 Installing And Wiring Your Module Read this chapter to install and wire your module This chapter covers Electrostatic avoiding electrostatic damage determining power requirements installing the module wiring signal cables to the module s terminal block Damage Electrostatic discharge can damage semiconductor devices inside this module if you touch backplane connector pins Guard against electrostatic damage by observing the following precautions CAUTION ELECTROSTATICALLY SENSITIVE COMPONENTS Before handling the module touch a grounded object to rid yourself of electrostatic charge e When handling the module wear an approved wrist strap grounding device e Handle the module from the front away from the backplane connector Do not touch backplane connector pins e Keep the module in its sta
101. nd that contamination of the thermocouple by impurities transferred from the alumina insulator can be reduced by heat treating the insulator prior to its use McLaren and Murdock 30 33 and Bentley and Jones 34 thoroughly studied the performance of type S thermocouples in the range 0 C to 1100 C They described how thermally reversible effects such as quenched in point defects mechanical stresses and preferential oxidation of rhodium in the type SP thermoelement cause chemical and physical inhomogeneities in the thermocouple and thereby limit its accuracy in this range They emphasized the important of annealing techniques The positive thermoelement is unstable in a thermal neutron flux because the rhodium converts to palladium The negative thermoelement is relatively stable to neutron transmutation Fast neutron bombardment however will cause physical damage which will change the thermoelectric voltage unless it is annealed out At the gold freezing point temperature 1064 18 C the thermoelectric voltage of type S thermocouples increases by about 340uV about 3 per 102 SLC 500 Universal Analog Input Module B Type Thermocouples weight percent increase in rhodium content the Seebeck coefficient increases by about 4 per weight percent increase at the same temperature ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for type S commercial thermoc
102. nts are the same that is the voltage versus temperature equations and tables for platinum versus type TN thermoelements apply to both types of thermoelements over the temperature range recommended for each thermocouple type However it should not be assumed that type TN and type EN thermoelements may be used interchangeably or that they have the same commercial initial calibration tolerances The low temperature research 8 by members of the NBS Cryogenics Division showed that the type T thermocouple may be used down to liquid 96 SLC 500 Universal Analog Input Module helium temperatures about 4 K but that its Seebeck coefficient becomes quite small below 20 K Its Seebeck coefficient at 20 K is only about 5 6uV K being roughly two thirds that of the type E thermocouple The thermoelectric homogeneity of most type TP and type TN or EN thermoelements is reasonably good There is considerable variability however in the thermoelectric properties of type TP thermoelements below about 70 K caused by variations in the amounts and types of impurities present in these nearly pure materials The high thermal conductivity of the type TP thermoelements can also be troublesome in precise applications For these reasons type T thermocouples are generally unsuitable for use below about 20 K Type E thermocouples are recommended as the most suitable of the letter designated thermocouple types for general low temperature use since they o
103. om the analog sensor connected to a specific channel will be translated for your application The bit status also informs you of any error condition and can tell you what type of error occurred The status word definitions for channels 0 through 3 do not include the RTD or resistance support that is provided by channels 4 through 7 The charts on the following pages provide a bit by bit examination of the respective status words Table 4 5 Channel 0 7 Status Word l e 0 through l e 7 Bit Definitions Channel 3 0 15 14 13 12 11 10 9 8 7 6 5 Ee hanne Get 4to 20 mA 0to 20 mA 0 05 V 0 10 V 0 50 V 2 0 V 0to5 V Input 1 to 5V Type 0 to 10V 10V Thermocouple Type J Thermocouple Type K Theromcouple Type T Thermocouple Type E Thermocouple Type R Thermocouple Type S Thermocouple Type B Thermocouple Type N Invalid Invalid Invalid Invalid Thermocouple Type C CJC temperature A w N o lo 990 oooooooo 5 0 0 HOM ROR OH 0 0 on on orm om Oo Engineering Units x1 0 0 Data Engineering Units x10 0 1l Format Scaled for PID 1 0 Proportional counts 1 1 Zero on open circuit 0 0 Open Max on open circuit 0 1 Circuit Min on open circuit 1 0 Disabled 1 1 Channel 10 Hz input filter 0 0 filter 50 Hz input filter 0 1 freq 60 Hz input filter 1 0 250 Hz input filter 1
104. on in Chapter 6 Testing Your Module before calling your local distributor of Spectrum Controls Note that your module contains electronic components which are susceptible to damage from electrostatic discharge ESD An electrostatic charge can accumulate on the surface of ordinary plastic wrapping or cushioning material In the unlikely event that the module should need to be returned to Spectrum Controls please ensure that the unit is enclosed in approved ESD packaging such as static shielding metallized bag or black conductive container Spectrum Controls reserves the right to void the warranty on any unit that is improperly packaged for shipment For further information or assistance please contact your local distributor or call Spectrum Controls Customer Satisfaction department at 425 746 9481 from 8 00 A M to 5 00 P M Pacific Time Available upon request 2001 2004 Spectrum Controls Inc All rights reserved Specifications subject to change without notice 500 are trademarks of Rockwell Automation Publication 0300172 03 Rev D May 2004 Printed in U S A Corporate Headquarters Spectrum Controls Inc P O Box 5533 Bellevue WA 98006 USA Fax 425 641 9473 Tel 425 746 9481 Web Site www spectrumcontrols com E mail spectrum spectrumcontrols com SPECTRUM C O N T R O L S AL AUTO S NGMPASS Roo yw The Encompass logo and SLC
105. ons you should know Use this guide if you design install program or maintain a control system that uses Allen Bradley Small Logic Controllers You should have a basic understanding of SLC 500 products You should also understand electronic process control and the ladder program instructions required to generate the electronic signals that control your application If you do not contact your local Allen Bradley representative for the proper training before using these products This guide covers the 1746sc NI8u universal analog input module It contains the information you need to install wire use and maintain these modules It also provides diagnostic and troubleshooting help should the need arise Table A lists several Allen Bradley documents that may help you as you use these products ii SLC 500 Universal Analog Input Modules Terms amp Abbreviations You Should Know Table A Related Allen Bradley documents Allen Bradley Doc No Title 1747 2 30 SLC 500 System Overview SGI 1 1 Application Considerations for Solid State Controls 1770 4 1 Allen Bradley Programmable Controller Grounding and Wiring Guidelines 1747 6 2 Installation amp Operation Manual for Modular Hardware Style Programmable Controllers 1747 NI001 Installation amp Operation Manual for Fixed Hardware Style Programmable Controllers 1747 6 4 Allen Bradley Advanced Programming Software APS User Manual 1747 6 11 Allen Bradley Advanced
106. or a mV V mA or resistance analog sensor enter a zero in bit 9 Determine the desired input filter frequency for the channel and enter the 2 digit binary code in bit field 11 12 of the channel configuration word A lower filter frequency increases the channel update time but also increases the noise rejection and channel resolution A higher filter frequency decreases the channel update time but also decreases the noise rejection and effective resolution Ifan RTD or resistance input type was selected enter the digit binary code corresponding to 2 or 4 wire or 3 wire RTD inputs in bit 13 If a thermocouple mV V or mA type is used enter a 0 in bit 13 Ifauto calibration is desired place a zero in bit 14 If auto calibration is not desired place a one in bit 14 Determine whether the channel input image word should contain data or status Place a one in bit 15 if channel data is desired Place a zero in bit 15 if status is desired Build the channel configuration word for every channel on each universal module repeating the procedures given in steps 1 9 11 Enter this configuration into your ladder program and copy it to the universal module Each channel has a word in the module s output image which determines the way that channel functions Channels 0 through 3 may be configured for current voltage or thermocouple input types No RTD or resistance input types are allowed on those channels Channels 4 t
107. ord is read into the N7 table High Lim 1000 LIM COP LIMIT TEST COPY FILE Low Lim 950 Source 1 2 0 Dest N7 10 Test T4 0 ACC Length 8 0 Chapter 5 Ladder Program Examples 61 Rung 2 3 This rung will copy the channel sensor data into registers N7 0 through N7 7 about 2 seconds after the configuration word has been changed to send sensor data Timing is important here Because the channels are multiplexed it can take the module some amount of time to update the channel input word with sensor data it has been sending channel status information That amount of time is determined by the module update time and the worst case autocalibration time that could occur based on the filter frequencies and input types selected LIM gt gt COP LIMIT TEST COPY FILE Low Lim 200 Source HI 2 0 Dest N7 0 Test T4 0 ACC Length 8 0 High Lim 750 Rung 2 4 This rung will set the channel configuration words for sending sensor data each time the timer completes a cycle It also resets the timer T4 0 FOR E FILL FILE DN Source 232617 Dest HO2 0 Length 8 END 62 SLC 500 Universal Analog Input Module Module and Channel Diagnostics Chapter6 Testing Your Module This chapter describes troubleshooting with channel status and module status LEDs It explains the types of conditions that might cause the module to flag an error and suggests what corrective
108. ouple inputs are cold junction compensated and are linearized in their temperature conversion process through the NIST ITS 90 tables RTDs are converted from their resistance value to degrees according to their associated IEC or JISC standards Scaling Examples Scaled for PID to Engineering Units Equation Engr Units Equivalent S S x Scaled for PID value displayed 16384 LOW men H LOW Assume type J input type scaled for PID display type channel data 3421 Want to calculate C equivalent From Channel Data Word Format table Size 210 C and S 760 C HIGH Solution Engr Units Equivalent 210 C 760 C 210 C x 3421 16384 7 46 C Engineering Units to Scaled for PID Equation Scaled for PID Equivalent 16384 x Engineering Units desired S 65 LOW HIGH Low Assume type J input type scaled for PID display type desired channel temp 344 C Want to calculate Scaled for PID equivalent From Channel Data Word Format table Siow 210 C and S 760 C HIGH Solution Scaled for PID Equivalent 16384 x 344 C 210 C 760 C 210 C 9357 40 SLC 500 Universal Analog Input Module Proportional Counts to Engineering Units Equation Engr Units Equivalent Sow t Susu Siow Proportional Counts value displayed 32768 65536 Assume type E input type proportional counts display type channel data 21567 Want to calculate F equivalent From Ch
109. ouples be 1 5 C or 0 25 whichever is greater between 0 C and 1450 C Type S thermocouples can be supplied to meet special tolerances of 0 6 C or 0 1 whichever is greater The suggested upper temperature limit 1480 C given in the ASTM standard 7 for protected type S thermocouples applies to AWG 24 0 51mm wire This temperature limit applies to thermocouples used in conventional closed end protecting tubes and it is intended only as a rough guide to the user It does not apply to thermocouples having compacted mineral oxide insulation Platinum 30 Rhodium Alloy Versus Platinum 6 Rhodium Alloy Thermocouples This type is sometimes referred to by the nominal chemical composition of its thermoelements platinum 30 rhodium versus platinum 6 rhodium or 30 6 The positive BP thermoelement typically contains 29 60 0 2 rhodium and the negative BN thermoelement usually contains 6 12 0 02 rhodium The effect of differences in rhodium content are described later in this section An industrial consensus standard 21 ASTM E1159 87 specifies that rhodium having a purity of 99 98 shall be alloyed with platinum of 99 99 purity to produce the thermoelements This consensus standard 21 describes the purity of commercial type B materials that are used in many industrial thermometry applications that meet the calibration tolerances described later in this section Both thermoelements will typically have sign
110. pear in word S 6 of the SLC processor status file The first two digits of the error code identify the slot in hexadecimal with the error The last two digits identify the I O error code in hexadecimal The error codes that apply to your module include in hexadecimal 50 5E 71 watchdog error 90 94 For a description of the error codes refer to the Allen Bradley Advanced Programming Software APS Reference Manual Allen Bradley publication 1746 6 11 Verifying With Test Instrumentation Chapter 6 Testing Your Module 67 The 1746sc NI8u has multiplexed channel inputs which switch in order to read an input channel The settling time is 3ms Caution must be used when testing the module with a test instrument because the instrument may require a settling time much greater than 3 ms Errors will result in the test instrument sourcing if its settling time requirement is not met Contact the instrumentation manufacturer for settling time requirements before using the instrument to test your module 68 SLC 500 Universal Analog Input Module Figure 6 1 Troubleshooting Flowchart Check LEDs on module Module Module Channel Status LED s Status LED Status LED s off on blinking Module fault Normal module condition operation Fault condition Check to see End that module is mV mA seated properly in chassis Cycle
111. port a maximum combined cable length associated with an overall cable impedance of 25 ohms or less without exceeding its input limitations The accuracy specifications provided herein do not include errors associated with unbalanced cable impedance Since the operating principle of the RTD and resistance inputs is based on the measurement of resistance take special care in selecting your input cable For 2 wire or 3 wire configuration select a cable that has a consistent impedance throughout its entire length For 2 wire configurations we recommend that you use Belden 9501 or equivalent For 3 wire configurations we recommend that you use Belden 9533 or equivalent for short installation runs less than 100 feet or use Belden 83503 or equivalent for longer runs greater than 100 feet and in high humidity environments Table 1 8 Cable Specifications Description When used Conductors Shield Insulation Jacket Agency Approval Temperature Rating Belden 9501 For 2 wire RTDs and potentiometers 2 24 AWG tinned copper 7x32 Beldfoil aluminum polyester shield w copper drain wire PVC Chrome PVC NEC Type CM 80 C Belden 9533 For 3 wire RTDs and potentiometers Short runs less than 100 feet and normal humidity levels 3 24 AWG tinned copper 7x32 Beldfoil aluminum polyester shield w copper drain wire S R PVC Chrome PVC NEC Type CM 80 C Belden 83503 For 3 wire RTDs a
112. portional counts are scaled to fit the defined temperature voltage or current range The input signal range is proportional to your selected input and scaled into a 32 768 to 32 767 range Using Scaled for PID and Proportional Counts The universal module provides eight options for displaying input channel data These are 0 1 F 0 1 C 1 F 1 C 0 01 mV 0 1 mV Scaled for PID and Proportional Counts The first six options represent real Engineering Units provided displayed by the 1746sc NI8u and do not require explanation The Scaled for PID and Proportional Counts selections provide the highest NI8u display resolution but also require you to manually convert the channel data to real Engineering Units The equations below show how to convert from Scaled for PID to Engineering Units Engineering Units to Scaled for PID Proportional Counts to Engineering Units and Engineering Units to Proportional Counts To perform the conversions you must know the defined temperature or millivolt range for the channel s input type Refer to the Channel Data Word Format table on the following page The lowest possible value for an input type is S and the highest possible value is S LOW HIGH It is important to note that the Scaled for PID and proportional counts format do not linearize inputs that are not linear The module assumes that current and voltage inputs are linear prior to insertion into the universal module s input stage Thermoc
113. put filter 0 0 filter 50 Hz input filter 0 1 freq 60 Hz input filter 1 0 250 Hz input filter 1 1 Open circuit No error 0 Open circuit detected 1 Under range No error 0 error Under range condition 1 Over 6 No error 0 error Over range condition 1 Channel No error 0 error Channel error 1 48 SLC 500 Universal Analog Input Module Important If the channel for which you are seeking status is disabled all bit fields are cleared The status word for any disabled channel is always 0000 0000 0000 0000 regardless of any previous setting that may have been made to the configuration word Explanations of the status conditions follow Channel Status Bit 0 The channel status bit indicates operational state of the channel When the channel enable bit is set in the configuration word bit 0 the universal module configures the selected channel and takes a data sample for the channel data word before setting this bit in the status word Input Type Status Bits 1 5 The input type bit field indicates what type of input signal you have configured for the channel This field reflects the input type defined in the channel configuration word Data Format Type Status Bits 6 and 7 The data format bit field indicates the data format you have defined for the channel This field reflects the data type selected in bits 6 and 7 of the channel configuration word Open Circuit Type Status Bits 8 and 9 The open circuit bit field indic
114. r wiring and as far as possible from sources of electrical noise such as motors 16 SLC 500 Universal Analog Input Module Wiring RTD or Resistance Sensors to the NI8u Module transformers contactors and ac devices As a general rule allow at least 6 in about 15 2 cm of separation for every 120 V of power Routing the field wiring in a grounded conduit can reduce electrical noise further Ifthe field wiring must cross ac or power cables ensure that they cross at right angles To limit the pickup of electrical noise keep thermocouple RTD millivolt and milliamp signal wires as far from power and load lines as possible For improved immunity to electrical noise use Belden 8761 shielded twisted pair or equivalent wire for millivolt sensors or use shielded twisted pair thermocouple extension lead wire specified by the thermocouple or RTD manufacturer Using the incorrect type of thermocouple extension wire or not following the correct polarity may cause invalid readings There is one shield pin for every two input channels All shields are internally connected so any shield terminal can be used with any channel Ground the shield drain wire at only one end of the cable The preferred location is at the shield connections on the terminal block Refer to IEEE Std 518 Section 6 4 2 7 or contact your sensor manufacturer for additional details Keep all unshielded wires as short as possib
115. range Figure 5 4 Dynamic programming example Program Listing Rung 2 0 Set up all eight channels s l COP f COPY FILE 15 Source N10 0 Dest 0 3 0 Length 8 Rung 2 1 Set channel 2 to CJC s l MOV B3 EA MOVE 0 CSR 0 Source N10 8 Dest 058 42 Runa 2 2 Set channel 2 back 10V LA re RI m 0 1 Source N10 2 Dest O73 2 Rung 2 3 I ENDI 54 SLC 500 Universal Analog Input Module Verifying Channel Figure 5 5 Data table for dynamic programming address 15 data 0 address 15 data 0 N10 0 1000 0011 0101 0011 N10 8 1000 0000 0111 1111 N10 1 1000 0011 0101 0011 N10 2 1000 0011 0101 0011 N10 3 1000 0011 0101 0011 N10 4 1000 0011 0101 0011 N10 5 1000 0011 0101 0011 N10 6 1000 0011 0101 0011 N10 7 1000 0011 0101 0011 Configuration Changes Important While the module performs the configuration alteration it does not monitor input device data change at any channel When executing a dynamic channel configuration change there will always be a delay from the time the ladder program makes the change to the time the NI8u gives you a data word using that new configuration information Therefore it is very important to verify that a dynamic channel configuration change took effect in the module particularly if the channel being dynamically configured is used for control The following example explains how to verify that channel configuration chan
116. ration word dynamic programming of the configuration word verifying channel configuration changes interfacing the universal module to a PID instruction monitoring channel status bit To enter data into the channel configuration word O e 0 through O e 7 when the channel is disabled bit 0 0 follow these steps Refer to page 30 Table 9 for specific configuration details Example Configure eight channels of a universal module residing in slot 3 of a 1746 chassis Configure each channel with the same parameters Figure 5 1 Channel configuration 15 14 13 12 11 10 9 8 7 6 d 211 0 1 0 0 0 0 0 1 1 0 1 0 1 1 0 1 1 Configure Channel For Channel Enable Bit 10 0 V Range Engineering Units x 10 Open Circuit Disabled Degrees C N A 10 Hz Filter RTD Type N A Auto cal Disable Bit Channel Data Word This example transfers configuration data and sets the channel enable bits of all eight channels with a single File Copy instruction SLC 500 Universal Analog Input Module Procedure 1 Using the memory map function create integer file N10 Integer file N10 should contain eight elements N10 0 through N10 7 2 Using the APS software data monitor function enter the configuration parameters for all eight universal channels into a source integer data f
117. rd 1 1 1 1 1 1 Channel 5 Configuration Word Channel 6 Configuration Word 1 1 1 1 1 1 1 Channel 7 Configuration Word 1 1 1 I 1 1 1 1 6 slot number of the module 34 SLC 500 Universal Analog Input Module Channel Configuration Procedure The configuration word default settings are all zero Next we describe how you set configuration bits of a channel configuration word to set up the following channel parameters type of thermocouple RTD resistance mV V or mA input RTD or resistance type of 2 wire 3 wire or 4 wire data format such as engineering units counts or scaled for PID how the channel should respond to a detected open input circuit if applicable filter frequency selection temperature units in C or F whether the channel is enabled or disabled whether auto calibration is enabled or disabled whether status or data information is selected for the module s input image table The channel configuration word consists of bit fields the settings of which determine how the channel will operate This procedure looks at each bit field separately and helps you configure a channel for operation Refer to the chart on the following page and the bit field descriptions that follow for complete configuration information 1 Determine which channels are used in your program and enable them Place a one in
118. rmocouples or RTDs either the sensor or the extension wire may be broken The voltage or current input wire may be cut or disconnected from the terminal block For RTDs only a short circuit of less than 3 ohms will also flag this error If either of the two CJC devices are removed from the module wiring terminal any input channel configured for either a thermocouple or CJC temperature input will be placed in an open circuit condition An input channel configured for millivolt volt milliamp or RTD input is not affected by CJC open circuit conditions The results of the data word in an open circuit condition depend upon the selection of bits 8 and 9 If zero is selected the channel data word is forced to 0 during an open circuit condition Selecting maximum forces the channel data word value to its full scale value during an open circuit condition The full scale value is determined by the selected input type and data format Selecting minimum forces the channel data word value to its low scale value during an open circuit condition The low scale value is determined by the selected input type and data format When the open circuit option applies disabling the open circuit selection may result in unintended operation on a failure because the returned data word value is unknown The open circuit error bit and the channel LED will flag the condition until the error is resolved 44 SLC 500 Universal Analog Input Module For
119. rmoelectric stability Temperature Its Measurement and Control in Science and Industry Vol 6 Schooley J F ed New York American Institute of Physics 1992 579 584 AppendixB Thermocouple Descriptions 111 57 Bentley R E The new nicrosil sheathed type N MIMS thermocouple an assessment of the first production batch Mater Australas 18 6 16 18 1986 58 Bentley R E Russell Nicrosil sheathed mineral insulated type N thermocouple probes for short term variable immersion applications to 1100C Sensors and Actuators 16 89 100 1989 59 Bentley R E Irreversible thermoelectric changes in type K and type N thermocouple alloys within nicrosil sheathed MIMS cable J Phys D 22 1908 1915 1989 60 Bentley R E Thermoelectric behavior of Ni based ID MIMS thermocouples using the nicrosil plus sheathing alloy Temperature Its Measurement and Control in Science and Industry Vol 6 Schooley J F ed New York American Institute of Physics 1992 585 590 61 Bentley R E Thermoelectric hysteresis in nicrosil and nisil J Phys E Sci Instrum 20 1368 1373 1987 62 Bentley R E Thermoelectric hysteresis in nickel based thermocouple alloys J Phys D 22 1902 1907 1989 112 SLC 500 Universal Analog Input Module Thermocouple Types Appendix C Using Grounded Junction Ungrounded Junction and Exposed Junction Thermocouples This appendix describes the types of thermocouples available
120. rocessors The module supports connections of up to eight channels of thermocouple current or voltage inputs OR four channels of RTD or resistance inputs and four channels of thermocouple current or voltage inputs Input Ranges The following tables provide compatibility information on the supported thermocouple types and their associated temperature ranges the supported RTD types and their associated temperature ranges as well as the millivolt volt milliamp and resistance input types supported by the NI8u module To determine the practical temperature range of your thermocouple refer to the specifications in appendices A and B Detailed accuracy specifications for all input types can be found in appendix A Table 1 1 Thermocouple Temperature Ranges Type C Temperature Range F Temperature Range J 210 C to 760 C 346 F to 1400 F K 270 C to 1370 C 454 F to 2498 F T 270 C to 400 C 454 F to 752 F B 300 C to 1820 C 572 F to 3308 F E 270 C to 1000 C 454 F to 1832 F R 0 C to 1768 C 32 F to 3214 F S 0 C to 1768 C 32 F to 3214 F N 0 C to 1300 C 32 F to 2372 F 6 0 C to 2315 C 32 F to 4199 F CJC Sensor 25 C to 105 C 13 F to 221 F SLC 500 Universal Analog Input Module Table 1 2 RTD Temperature Ranges C Temperature Range F Temperature Range 200 C to 850 C 328 F to 1562 F 200 C to 750 C 328 F to 1382 F 200 C to 850 C 328
121. roperties of this thermocouple have been described by Sparks and Powell 12 Type E thermocouples also have the largest Seebeck coefficient above 0 C for any of the letter designated thermocouples For that reason they are being used more often whenever environmental conditions permit Type E thermocouples are recommended by the ASTM 5 for use in the temperature range from 200 C to 900 C in oxidizing or inert atmospheres If used for extended times in air above 500 C heavy gage wires are recommended because the oxidation rate is rapid at elevated temperatures About 50 years ago Dahl 11 studies the thermoelectric 98 SLC 500 Universal Analog Input Module stability of EP and EN type alloys when heated in air at elevated temperatures and his work should be consulted for details More recent stability data on these alloys in air were reported by Burley et al 13 Type E thermocouples should not be used at high temperatures in sulfurous reducing or alternately reducing and oxidizing atmospheres unless suitably protected with protecting tubes They also should not be used in vacuum at high temperatures for extended times because the chromium in the positive thermoelement a nickel chromium alloy vaporizes out of solution and alters the calibration In addition their use in atmospheres that promote green rot corrosion of the positive thermoelement should be avoided Such corrosion results from the preferential oxidatio
122. rsus Platinum Thermocouples This type is often referred to by the nominal chemical composition of its positive SP thermoelement platinum 10 rhodium The negative SN thermoelement is commercially available platinum that has a nominal purity of 99 99 21 An industrial consensus standard ASTM E1159 87 specifies that rhodium having a nominal purity of 99 98 shall be alloyed with platinum of 99 99 purity to produce the positive thermoelement which typically contains 10 00 0 05 rhodium by weight The consensus standard 21 describes the purity of commercial type S materials that are used in many industrial thermometry applications and that meet the calibration tolerances described later in this section It does not cover however the higher purity reference grade materials that traditionally were used to construct thermocouples used as standard instruments of the IPTS 68 as transfer standards and reference thermometers in various laboratory applications and to develop reference functions and tables 27 28 The higher purity alloy material typically contains less than 500 atomic ppm of impurities and the platinum less than 100 atomic ppm of impurities 27 Difference between such high purity commercial material and the platinum thermoelectric reference standard Pt 67 are described in 27 and 28 A reference function for the type S thermocouple based on the ITS 90 and the SI volt was determined recently from new data obtained
123. s LED operates with status bits in the channel status word to indicate the following faults detected by the module invalid channel configuration e an open circuit input out of range errors selected filter frequency data acquisition or auto calibration errors When the module detects any of the following fault conditions it causes the channel status LED to blink and sets the corresponding fault bit in the channel status word Channel fault bits bits 12 15 and channel status LEDs are self clearing when fault conditions are corrected Open circuit Detection Bit 12 If open circuit is enabled for an applicable input channel the module tests the channel for an open circuit condition each time it scans its input Open circuit detection is always performed for the CJC inputs Open circuit does not apply to 2V 0 5V 1 5V 10V 0 10V or 0 20mA ranges Possible causes of an open circuit include broken thermocouple RTD or CJC sensor thermocouple RTD or CJC sensor wire cut or disconnected e millivolt volt or milliamp input wire cut or disconnected less than 3 ohms has been detected on an RTD input Out of Range Detection Bit 13 for under range bit 14 for over range The module tests all enabled channels for an out of range condition each time it scans its inputs Possible causes of an out of range condition include the temperature is too hot or too cold for the thermocouple or RTD being used
124. sec 314 msec 314 msec 314 msec 314 msec 2 826 sec 30 SLC 500 Universal Analog Input Module Channel Turn On Turn Off and Reconfiguration Times Auto Calibration Note On alternate module scans the 314 msec lead resistance sampling time would be replaced by a 64 msec CJC sampling time Update Time Calculation Example The following example shows how to calculate the module update time for the given configuration Channel 0 configured for mV input at 250 Hz filter frequency enabled Channel 1 configured for mV input at 250 Hz filter frequency enabled Channel 2 configured for mV input at 50 Hz filter frequency enabled Channel 3 disabled Channel 4 configured for RTD input at 50Hz filter frequency enabled Channel 5 through 7 disabled Using the values from the table above add the sum of all enabled channel sample times plus one 50 Hz lead resistance update time Channel 0 sampling time 26 msec Channel sampling time 26 msec Channel 2 sampling time 74 msec Channel 4 sampling time 74 msec Lead Resistance Sampling time 74 msec Module update time 274 msec The time required for the module to recognize a new configuration for a channel is generally one module update time plus 1 865 msec per newly configured channel If the filter frequency selected for the newly enabled configured channel is new to the module then auto calibration will be performed following configuration recognition Turn off
125. selective testing of materials as well as special preparatory heat treatments beyond those given by the manufacturer will usually be necessary Bentley s articles 61 62 should be consulted for guidelines and details ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for type N commercial thermocouples be 2 2 C or 0 75 whichever is greater between 0 C and 1250 C Type N thermocouples can also be supplied to meet special tolerances that are equal to approximately one half the standard tolerances given above Tolerances are not specified for type N thermocouples below 0 C The suggested upper temperature limit of 1260 C given in the ASTM standard 7 for protected type N thermocouples applies to AWG 8 3 25mm wire It decreases to 1090 C for AWG 14 1 63mm 980 C for AWG 20 0 81mm 870 C for AWG 24 or 28 0 51mm or 0 33mm and 760 C for AWG 30 0 25mm These temperature limits apply to thermocouples used in conventional closed end protecting tubes and they are intended only as a rough guide to the user They do not apply to hermocouples having compacted mineral oxide insulation 106 SLC 500 Universal Analog Input Module References 1 Preston Thomas H The International Temperature Scale of 1990 ITS 90 Metrologia 27 3 10 1990 ibid p 107 2 The International Practical Temperature Scale of 1968 Amended Edition of 1975 Metrologia 1
126. self clearing when fault conditions are corrected Important If you clear the channel enable bit channel status bits are reset The module has nine LEDs eight channel status LEDs numbered to correspond with each channel one module status LED INPUT Channel UO 14 lt LED for Module Status LEDs for Channels 0 7 Module BO gt Universal Analog LED Troubleshooting Tables Table 6 1 Module status LED If Module Status LED is Then Take this Corrective Action On The module is OK No action required off The module is turned off Cycle power If the condition persists or it detected a module call your local distributor or Spectrum fault Controls for assistance Table 6 2 Module status and Channel status LED If Module Status And Channel Take this Corrective Action LED is Status LED is On The channel No action required is enabled Blinking The module Examine error bits in status word detected if bit 12 1 the input has an open circuit On open circuit condition if bit 13 1 the input value is under range under range condition if bit 14 1 the input value is over range over range condition if bit 15 1 the channel has a diagnostic channel error or channel error The module is in No action is required power up or the channel is disabled Chapter 6 Testing Your Module 65 Channel status LEDs Green The channel statu
127. speed versus resolution trade off CJC inputs are sampled at 60 Hz Select RTD Type Bit 13 The selection for RTD or resistance type is only valid for channels 4 through 7 and should be set to zero for channels 0 through 3 If the Input Type selection defines an RTD or resistance type then the wire type also needs to be specified The universal module converts the RTD or resistance type input data differently according to whether the 2 or 4 wire method is used or the 3 wire method is used Select Auto Calibration Disable Bit 14 The auto calibration disable bit allows you to disable periodic auto calibration Set this bit on any enabled channel to disable auto calibration for all channels Clear this bit on all enabled channels to enable auto calibration on all channels Channel Data Status Word Chapter 4 Channel Configuration Data and Status 45 Select Input Image Type Bit 15 The input image type bit allows you to select data or status information in the channel s input image word When set 1 the module places channel data in the corresponding input image word When the bit is cleared 0 the module places channel status in the corresponding input image word The actual thermocouple RTD resistance millivolt volt or milliamp input data values or channel status reside in I e 0 through I e 7 of the universal module input image file The data values present will depend on the input type and data formats you have sel
128. sulating the thermocouple High purity alumina with low iron content appears to be the most suitable material for the purpose Type B thermocouples should not be used in reducing atmospheres nor those containing deleterious vapors or other contaminants that are reactive with the platinum group metals 42 unless suitably protected with nonmetallic protecting tubes They should never be used in metallic protecting tubes at high temperatures The Seebeck coefficient of type B thermocouples decreases with decreasing temperature below about 1600 C and becomes almost negligible at room temperature Consequently in most applications the reference junction temperature of the thermocouple does not need to be controlled or even known as long as it between 0 C and 50 C For example the voltage developed by the thermocouple with the reference junction at 0 C undergoes a reversal in sign at about 42 C and between 0 C and 50 C varies from a minimum of 2 6uV near 21 C to 8 maximum of 2 3uV at 50 C Therefore in use if the reference junction of the thermocouple is within the range 0 C to 50 C then a 0 C reference junction temperature can be assumed and the error introduced will not exceed 3uV At temperatures above 1100 C an additional measurement error of 3uV about 0 3 C would be insignificant in most instances ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for t
129. t of oxidation on stability of thermocouples Proceedings of the American Society for Testing and Materials Vol 63 1185 1194 1963 19 Bentley R E Short term instabilities in thermocouples containing nickel based alloys High Temperatures High Pressures 15 599 611 1983 20 Kollie T G Horton J L Carr K R Herskovitz M B Mossman C A Temperature measurement errors with type K Chromel vs Alumel thermocouples due to short ranged ordering in Chromel Rev Sci Instrum 46 1447 1461 1975 21 ASTM American Society for Testing and Materials Standard E1159 87 1992 Annual Book of ASTM Standards Vol 14 03 Philadelphia ASTM 1992 388 389 22 Bedford R E Ma C K Barber C R Chandler T R Quinn T J Burns G W Scroger M New reference tables for platinum 10 rhodium platinum and platinum 13 rhodium platinum thermocouples Temperature Its Measurement and Control in Science and Industry Vol 4 Part 3 p 1585 Plumb H H ed Pittsburgh Instrument Society of America 1972 23 Burns G W Strouse G F Mangum B W Croarkin M C Guthrie W F Chattle M New reference functions for platinum 13 rhodium versus platinum type R and platinum 30 rhodium versus platinum 6 rhodium type B thermocouples based on the ITS 90 in Temperature Its Measurement and Control in Science and Industry Vol 6 Schooley J F ed New York American Institute of Physics 1992 559 564
130. th a 200A current source 1Q of lead resistance adds 200uV or 3 45 C error with the 100Q 385 alpha type To gain an understanding of how lead resistance affects RTD readings the uV C for each RTD type is listed below The current source is 200HA 18 SLC 500 Universal Analog Input Module Preparing and Wiring the Cables RTD Type VIC 100Q Pt 385 58uV C 2000 Pt 385 116uV C 5000 Pt 385 290uV C 10009 Pt 385 580pV PC 1000 Pt 3916 68uV C 200 Pt 3916 136uV C 5000 Pt 3916 340pV FC 10000 Pt3916 680uV C 10Q Cu 426 4 3pV PC 1209 Ni 618 110uV C 1209 Ni 672 130uV C The accuracies specified for the NI8u RTDs do not include errors due to lead resistance imbalances Important To ensure temperature or resistance value accuracy the resistance difference of the cable lead wires must be equal to or less than 0 01 ohms There are several ways to insure that the lead values match as closely as possible They are as follows Keep total lead resistance as small as possible and less than 25 ohms Use quality cable that has a small tolerance impedance rating Use a heavy gauge lead wire which has less resistance per foot To prepare and connect cable leads and drain wires follow these steps Signal Wires Remove foil shield and drain wire Cable SS from sensor end of cable Drain Wire Signal Wires At the module end of the cable extract the drain wire but remove the foil shield 1
131. thermocouple RTD resistance and millivolt volt and milliamp inputs for the NI8u module SLC 500 Universal Analog Input Module The accuracies specified as follows include errors due to the cold junction compensation for thermocouples current source errors for RTDs and hardware and software errors associated with the system which depends upon input path RTD accuracies do not include errors due to lead resistance The hardware and software errors include calibration of the system and non linearity of the ADC For the sake of the calculations the resolution of the ADC was assumed to be at least 16 bits use of the 10Hz 50Hz and 60Hz filter frequencies Note The 250Hz frequency should not be applied to thermocouple or RTD inputs if accuracy is a concern Thermocouple The following table provides the maximum error for each thermocouple type when the 10Hz 50Hz or 60Hz filters are used and the module is operating at 25 C and was calibrated at 25 C Inaccuracies in the cold junction compensation sensors are not included Thermocouple Max Error Type 25 C J 0 6 C K 225 C to 1370 C 0 K 270 Cto 225 C 7 5 C T 230 Cto 400 C 0 T 270 C to 230 C 5 4 C E 210 Cto 1000 C 6 E 270 C to 210 C 6 R 1 7 C S 1 7 C B 3 0 C N 0 4 C C 1 8 C The following table provides the maximum error for each thermocouple type when the 10Hz 50Hz or 60Hz filters are used and the module is operating at 09C
132. tic shield container when not in use or during shipment Failure to observe these precautions can degrade the module s performance or cause permanent damage Power Requirements The module receives its power through the SLC 500 chassis backplane from the fixed or modular 5 VDC and 24 VDC chassis power supply The maximum current drawn by the module is shown in the table below 10 SLC 500 Universal Analog Input Module Shunt Configuration Table 2 1 Maximum current drawn by the module 5VDC Amps 24VDC Amps 0 120 0 100 When using the module in a modular system add the values shown above to the requirements of all other modules in the SLC to prevent overloading the chassis power supply When using the module in a fixed controller be sure not to exceed the power supply rating for the 2 slot I O chassis Considerations for a Modular System Place your module in any slot of an SLC 500 modular or modular expansion chassis except for the left most slot slot 0 reserved for the SLC processor or adapter modules Considerations for a Fixed Controller The power supply in the 2 slot SLC 500 fixed I O chassis 1746 A2 can support only specific combinations of modules Make sure the chassis power supply can support the NI8u and additional module power requirements The 1746sc NI8u module is a multi purpose multi functional module that is capable of supporting many different input types in a very small package Ther
133. time requires up to one module update time Reconfiguration time is the same as turn on time Auto calibration is performed by the module to correct for drift errors over temperature Auto calibration occurs immediately following configuration of a previously unselected filter frequency for the particular input path If all enabled channels have the calibration disable configuration bit set to zero auto calibration also occurs as a continuous cycle where every two minutes all the required filter frequencies and input paths are calibrated There are three input paths in the system to accommodate all the input options alow voltage input path Chapter 3 Things To Consider Before Using Your Module 31 amid voltage input path and a high voltage input path The following table correlates input type to input path Input Type Input Path 4 to 20mA Mid 0 to 20mA Mid 50mV Low 100mV Low 500mV Mid 2V Mid 0 to 5V LAN High 10V 0 10V High All Thermocouple Types Low Pt 385 RTD 100Q Low Pt 385 RTD 200 5000 10000 Mid Pt 385 RTD 100Q Low Pt 385 RTD 2000 500 10000 Mid Cu 426 RTD 10Q Ni 618 RTD 1200 Ni 672 RTD 1200 CIC 3000Q Resistance Mid Each input path supports four different filter frequencies 10Hz 50Hz 60Hz and 250Hz The following table indicates auto calibration time based on the input path and the selected filter frequency Input Path
134. tion connect to mV devices keeping the leads short Important If noise persists try grounding the opposite end of the cable instead Ground one end only Important For CE compliance Ferrite EMI Suppressors are needed on each channel s terminal block connection If remote CJCs are installed shielded wire must be used and a Ferrite EMI suppressor is needed on each CJC input connection The drain wire of the CJC cable must be connected to a shield connection at the module Apply the suppressor close to the module terminal block as shown below A Steward Part 28B2024 0A0 or equivalent is recommended The Steward 28B2024 0A0 has an impedance of 157Q at 25 MHz 256Q at 100 MHz and can accomodate one turn of wire SLC 500 Universal Analog Input Module Figure 2 3 Ferrite EMI suppressor for CE compliance Module Note Please refer to Appendix C for additional information on wiring and using grounded junction ungrounded junction and exposed juction thermocouple types Figure 2 4 Terminal block diagram with cable THERMOCOUPLE mA mV or V CABLE AHIs 4 WIRE RTD CABLE 3 WIRE RTD CABLE 4 D THERMOCOUPLE mA mV or V CABLE HHS input CHO CHO Shield for CHO and CH1 CH1 CH1 EXC4 CH4 CH4 EXC4 Shield for CH4 and CH5
135. to 60 C and was calibrated at that temperature Inaccuracies in the cold junction compensation sensors are not included Thermocouple Max Error Type 0 C to 60 C J 0 9 C K 225 C to 13700 0 K 270 Cto 225 C 10 0 C T 230 Cto 400 C 5 0 T 270 C to 0 7 0 C E 210 Cto 1000 C 0 8 C E 270 Cto 210 C 6 3 C R 2 6 C S 2 6 C B 0 0 6 C C 3 5 C Appendix A Module Specifications 77 The diagrams that follow for each thermocouple type give data for a sample module over the input range of the thermocouple over temperature Thermocouples are usually parabolic in their nV to degrees C curves Normally at the ends of any given thermocouple range the ratio of change in temperature increases as a result of a change in voltage In other words at the ends a smaller change in voltage results in a larger change in degrees Thermocouple Type J Example Deviations 0 1 0 05 0 E 5 0 05 3 01 Ch 2 Delta 25C a Ch 2 Delta OC g 0 15 Ch 2 Delta 60C 0 2 o A 0 25 0 3 0 35 r r r r r r r i r r 210 110 10 90 190 290 390 490 590 690 790 Degrees C TC Input Thermocouple Type K Example Deviations Low Range E 2 3 m Ch 2 Delta 25C S Ch 2 Delta OC FA Ch 2 Delta 60C HI o o A 0 5 270 260 250 240 230 220 210 200 Degrees C TC Input 78 SL
136. type above 760 C If type J thermocouples are taken to high temperatures especially above 900 C they will lose the accuracy of their calibration when they are recycled to lower temperatures If type J thermocouples are used in air at temperatures above 760 C only the largest wire AWG 8 3 3mm should be used and they should be held at the measured temperature for 10 to 20 minutes before readings are taken The thermoelectric voltage of the type J thermocouples may change by as K Type Thermocouples AppendixB Thermocouple Descriptions 93 much as 40uV or 0 6 C equivalent per minute when first brought up to temperatures near 900 C ASTM Standard E230 87 in the 1992 Annual Book of ASTM Standards 7 specifies that the initial calibration tolerances for type J commercial thermocouples be 2 2 C or 0 75 whichever is greater between 0 C and 750 C Type J thermocouples can also be supplied to meet special tolerances which are equal to approximately one half the standard tolerances given above Tolerances are not specified for type J thermocouples below 0 C or above 750 C The suggested upper temperature limit of 760 C given in the above ASTM standard 7 for protected type J thermocouples applies to AWG 8 3 25mm wire For smaller diameter wires the suggested upper temperature limit decreases to 590 C for AWG 14 1 63mm 480 C for AWG 20 0 81mm 370 C for AWG 24 or 28 0 51mm or 0 33mm and 320 C for AWG 30 0 25mm
137. ugh the utilization of a combination of counters and timers If you are utilizing an SLC 5 03 or SLC 5 04 or later processor the internal processor clock registers S 40 to S 42 could be utilized to determine the timing Rung 2 0 e ES Timer T4 0 counts out a 10 second interval Its accumulator indicates the progress it has made toward completion The accumulator value shall be utilized to determine when to set the channel configuration word to send sensor data or to send status information A longer interval between transitions can be achieved using a combination of timers and counters 60 SLC 500 Universal Analog Input Module Rung 2 1 This rung tests to see if T4 0 ACC is at a value between 800 and 950 counts If so the channel configuration words are defined through the Fill File command to send status information LIM FLL LIMIT TEST I FILL FILE Low Lim 800 Source 1 Dest 0 2 0 Test T4 0 ACC Length 8 0 High Lim 950 Rung 2 2 This rung executes a Copy File command to move the channel status word as enabled in the previous rung into registers N7 10 through N7 17 for all channels Though the module is quick about switching from sensor data to status information it is a good idea to give the module a little time to switch modes That is why this example uses a half second period in time between when the channel is set up to send the status word and when the status w
138. ype B commercial thermocouples be 0 5 between 870 C and 1700 C Type B thermocouples can also be supplied to meet special tolerances of 0 25 Tolerances are not specified for type B thermocouples below 870 C The suggested upper temperature limit of 1700 C given in the ASTM standard 7 for protected type B thermocouples applies to AWG 24 0 5 1mm wire This temperature limit applies to thermocouples used in conventional closed end protecting tubes and it is intended only as a rough guide to the user It does not apply to thermocouples having compacted mineral oxide insulation Nickel Chromium Silicon Alloy Versus Nickel Silicon Magnesium Alloy Thermocouples This type is the newest of the letter designated thermocouples It offers higher thermoelectric stability in air above 1000 C and better air oxidation resistance than types E J and K thermocouples The positive thermoelement NP is an alloy that typically contains about 84 nickel 14 104 SLC 500 Universal Analog Input Module to 14 4 chromium 1 3 to 1 6 silicon plus small amounts usually not exceeding about 0 1 of other elements such as magnesium iron carbon and cobalt The negative thermoelement NN is an alloy that typically contains about 95 nickel 4 2 to 4 6 silicon 0 5 to 1 5 magnesium plus minor impurities of iron cobalt manganese and carbon totaling about 0 1 to 0 3 The type NP and NN alloys were known originally 16 as nicrosil and

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