PMI-8S - BD Simex
Contents
1. 900 X11 PH 100 Y11 PH 820 and lp 0 9 for these values the returned value W 795 14 User manual for module with analogue inputs PMI 8S 7 THE MODBUS PROTOCOL HANDLING Transmission parameters 1 start bit 8 data bits 1 stop bit no parity control Baud rate selectable from 1200 to 115200 bits sec Transmission protocol MODBUS RTU compatible The device parameters and display value are available via RS 485 interface as HOLDING type registers numeric values are given in U2 code of Modbus RTU protocol The registers or groups of the registers can be read by 03h function and wrote by O6h single registers or 10h group of the registers accordingly to Modbus RTU specification Maximum group size for 03h and 10h functions cannot exceeds 16 registers for single frame 1 i The device interprets the broadcast messages but then do not sends the answers A 7 1 LIST OF REGISTERS Register Write Range Register description Oth No 10000 10000 Result of channel 1 02h No 10000 10000 Result of channel 2 03h No 10000 10000 Result of channel 3 04h No 10000 10000 Result of channel 4 05h No 10000 10000 Result of channel 5 06h No 10000 10000 Result of channel 6 07h No 10000 10000 Result of channel 7 08h No 10000 10000 Result of channel 8 09h No 0000h FFFFh Status register for channels 1 8 20h Yes 1 FFh Device address New devi2. DIN rail mounted 35 mm rail 101 x 22 5 x 80 mm 0 C to 50 C 10 C to 70 C 5 to 90 no condensation up to 2000 meters above sea level 0 5 Nm 25 mm according to PN EN 61326 This is a class A unit In housing or a similar area it can cause radio frequency f _ _ preventive measures A 1 interference In such cases the user can be requested to use appropriate User manual for module with analogue inputs PMI 8S 4 DEVICE INSTALLATION The unit has been designed and manufactured in a way assuring a high level of user safety and resistance to interference occurring in a typical industrial environment In order to take full advantage of these characteristics installation of the unit must be conducted correctly and according to the local regulations Read the basic safety requirements on page 3 prior to starting the installation Ensure that the power supply network voltage corresponds to the nominal voltage stated on the unit s identification label The load must correspond to the requirements listed in the technical data All installation works must be conducted with a disconnected power supply 4 1 UNPACKING After removing the unit from the protective packaging check for transportation damage Any transportation damage must be immediately reported to the carrier Also write down the unit serial number on the housing and report the damage to the manufacturer Attached with th
3. m ro O gt m gt User defined characteristic User defined characteristic is defined as set of X Y points Number of the points is variable and may be set from 2 to 20 points which make linear segments see graph and see LISTOF REGISTERS Due to the normalized result In the device computes specific segment e g for characteristic from figure below and In 0 65 the segment between points X 50 0 and X 70 0 will be chosen Let s mark those points as PL point low i PH point high in this example PL 50 0 and PH 70 0 and the normalized result In for the point PL as lp in this example lp In PL 0 5 The returned result is calculated accordingly to the expression Y PH Y PT W I 1 x rt al X TX PH X PL x 100 Y PL where Y PH X PH Y PL X PL mean values of X and Y coordinates of PH i PL points fe If the normalized result exceeds the user defined characteristic values then specific 1 utmost segment defined by two next points is used for calculations If characteristic N from figure below is used and if In gt 1 then segment defined by points X PL 90 0 X PH 100 0 will be used 11 User manual for module with analogue inputs PMI 8S Normalized measurement In for 0 20 mA range 0 0 2 0 35 0 5 0 7 0 9 1 5 elements characteristic X PH 70 0 Y PL Returned value 0 4 8
4. new device address 2 The answer the same as the message ADDR FUNC REG H L DATA H L CRC L H 01 06 00 20 00 02 09 C1 18 User manual for module with analogue inputs PMI 8S 4 Change of baud rate of all devices connected to the net BROADCAST message ADDR FUNC REG H L COUNT H L CRC L H 00 06 00 22 00 04 29 D2 DATAH 0 DATA L 4 new baud rate 19200 baud 1 Device do not reply to BROADCAST type messages u 5 Try to write illegal data value into baud rate register ADDR FUNC REG H L DATA H L CRC L H 01 06 00 22 00 09 E9 C6 DATA L 9 value exceeds allowable range 0 7 The answer exception code O3h illegal data value ADDR FUNC ERR CRC L H 01 86 03 02 61 ERROR error code in this case 03h illegal data value ie i There is no full implementation of the Modbus Protocol in the device The 4 L functions presented above are available only 19 BD SIMIEX lt a division of BD SENSORS BD Sensors GmbH BD Sensors StraBe 1 95199 Thierstein Germany Telefon 49 0 9235 9811 2099 Telefax 49 0 9235 9811 860 e mail info bdsimex de www bdsimex de 04 2010
5. 12 16 20 Input current mA Figure 6 4 Example of user defined characteristic 6 2 EXAMPLES OF CALCULATIONS Example 1 Selection of the permissible input range 4 20 mode If in 4 20 mode the user sets Lo r 20 0 and Hi r 10 0 then permissible input currents range will be equal 3 2 mA 22 mA Lower border of the range is the result of calculations 4 mA 4 mA x 20 and the higher 20 mA 20 mA x 10 Example 2 The normalized I result calculation Let the input mode 4 20 mA The normalized In result is calculated accordingly to the expression on page 9 so if lin 10 mA then 10 mA 4 mA 6 mA and this result should be divided by the width of input range 16 mA Finally the normalized result In 6 16 0 375 In case when input current exceeds nominal measurement range calculations are similar For example if input current is equal 2 5 mA then In 2 5 4 16 0 0938 and if input current is equal 20 5 mA then In 20 5 4 16 1 0313 Example 3 The linear characteristic Let the input mode 4 20 mA and parameters Lo CAL and Hi CAL equal to 300 and 1200 respectively The calculations will be done for there different input currents from example 2 12 User manual for module with analogue inputs PMI 8S a In 10 mA and In 0 375 Accordingly to expression on page 10 for linear characteristic 0 375 x 1200 300 337 and next the Lo CAL value is added to the r
6. Device signalizes overload of nominal measurement range independently for every channel All available device parameters can be set via RS 485 interface see LIST OF REGISTERS page 15 Proper operation of the module is signalized by flashing green LED marked RUN and localized on front panel of the device Red LED marked Tx ERROR signalizes data transmission over serial interface by short flashes when this diode lights constantly it means that some error occurred User manual for module with analogue inputs PMI 8S Forcing of OxFF address New devices has set to Modbus addresses OxFE To enhance system installation process special operation mode has been developed It allows to force address OxFF in single module using internal momentary switch mounted on module mainboard Figure 4 1 To change address of the device to FFh wait for a moment after power up until green LED RUN starts flashes Next press and hold push button about 4 seconds until green LED will lights permanently then release push button The device changes its MODBUS address to FFh and waits for a new address readdressing Green LED RUN stay permanently on until readdressing via RS 485 or power off While module is in this state it is possible to control its inputs and communication is possible using temporal address FFh At this moment MASTER controller should find new device and readdress it to address other than OxFF and OxFE After remote readdres
7. IF THE DEVICE IS NOT USED ACCORDING TO THE MANUAL THE USER IS RESPONSIBLE FOR POSSIBLE DAMAGES This symbol denotes especially important characteristics of the unit Read any d J information regarding this symbol carefully User manual for module with analogue inputs PMI 8S 1 BASIC REQUIREMENTS AND USER SAFETY The manufacturer is not responsible for any damages caused by inappropriate installation not maintaining the proper technical condition and using the unit against its destination Installation should be conducted by qualified personnel During installation all available safety requirements should be considered The fitter is responsible for executing the installation according to this manual local safety and EMC regulations The unit must be properly set up according to the application Incorrect configuration can cause defective operation which can lead to unit damage or an accident If in the case of a defect of unit operation there is a risk of a serious threat to the safety of people or property additional independent systems and solutions to prevent such a threat must be used Neighbouring and mating equipment must meet the requirements of appropriate standards and regulations concerning safety and be equipped with adequate anti overvoltage and anti interference filters Do not attempt to disassemble repair or modify the unit yourself The unit has no user serviceable parts Units in which a defect w
8. characteristic no decimal point included oO N after writing to register no 20h the device responds witch an old address in the message after writing to register no 22h the device responds with the new baud rate the value of this parameter is also connected to write to this register so it is possible to block a writes but impossible to unblock writes via RS 485 interface The unblocking of the writes is possible by device reset only see Forcing of OxFF address page 9 the pairs of X Y coordinates may be defined for any free point The pair is free it means that particular point is not defined if X coordinate of this point is equal 8000h After writing both X and Y coordinate the point is defined and used in calculation of result The coordinates of any point can be changed at any time Content of channel parameters block Relative Description address Write Range Measurement range 0 1 current version 0 0 20 mA current version or 0 10 V voltage version 0 Yes 0 13 voltage version 1 4 20 mA current version or 2 10 V voltage version i 9 2 0 5 V voltage version only 3 1 5 V voltage version only Vos 0 3 Channel characteristic 0 linear 1 square 2 square root 3 user defined f Digital filter exponential u Yes vn 0 no filtration 5 maximum filtration Parameter Lo CAL 3 Yes 10000 10000 This value is
9. expression for all modes For example if input is set to 4 20 mode then upper border is calculated due to expression Imax 20 mA 20 mA x Hi r The value of Hi r can be set from 0 to 19 9 In example no 1 of the MEASURED VALUES CALCULATION paragraph the procedure of the permissible input range determining is presented in details When linear square or square root characteristic is chosen then the values returned in measurement registers 01h to 08h registers are defined by Lo CAL and Hi CAL parameters These parameters describe the values returned for minimum and maximum input value For example if input type is set to 4 20 mA Lo CAL parameter defines the value returned when input current is equal 4 mA and Hi CAL parameter defines the value returned for 20 mA of input current Available range for these parameters 999 9999 When user defined multipoint characteristic is chosen then the values returned in measurement registers 01h to 08h registers are calculated according to coordinates defined by user X Y points maximal 20 points Coordinate X defines the percentage ratio of input value to selected measurement range The X range 99 9 199 9 Coordinate Y defines the value returned in measurement register for particular X coordinate The Y value can be changed in range 999 9999 Settings of every channel are stored in nonvolatile EEPROM memory
10. mA and do 1 not exceed the permissible input range then received normalized In result will SE exceed 0 1 range e g input range 4 20 mA input current 3 mA the normalized result is equal 0 0625 and for input current 22 mA the normalized result is equal 1 125 In such cases presented expressions are still correct 6 1 ADDITIONAL CALCULATIONS USED CONVERSION CHARACTERISTIC The manner of the additional computation of the returned result depends on selected conversion characteristic All presented charts are connected with the input range 4 20 mA User manual for module with analogue inputs PMI 8S Linear characteristic The normalized result is converted by fixed coefficients determined by Lo CAL and Hi CAL parameters when the normalized results is equal 0 then value Lo CAL is returned and when the normalized results is equal 1 then value Hi CAL is returned Expression presented below shows the manner of result calculation W 1 x Hi CAL Lo CAL Lo CAL where W means the value returned in measurement register fe The value of the Lo CAL parameter can be higher than the value of Hi CAL J parameter In such a case for an increasing value of input current the returned a value decreases O b r o O O gt r Returned value Returned value m O O gt r O gt Pr oO gt 8 12 16 20 Input current mA oO gt 8 12 16
11. voltage or current inputs depending on version front view bottom view Figure 4 1 Terminals description User manual for module with analogue inputs PMI 8S AN e When use of SMPS it is strongly recommended to connect PE wire e All connections must be made while power supply is disconnected max 2 mm Figure 4 2 Method of cable insulation replacing and cable terminals 4 3 MAINTENANCE The unit does not have any internal replaceable or adjustable components available to the user Pay attention to the ambient temperature in the room where the unit is operating Excessively high temperatures cause faster ageing of the internal components and shorten the fault free time of unit operation In cases where the unit gets dirty do not clean with solvents For cleaning use warm water with small amount of detergent or in the case of more significant contamination ethyl or isopropyl alcohol an A Using any other agents can cause permanent damage to the housing Product marked with this symbol should not be placed in municipal waste Please check local regulations for disposal and electronic products 5 PRINCIPLE OF OPERATION The Module allows to measurement analog values from 8 current or voltage inputs with speed rate about 10 Hz every channel Measurement results can be internally recalculated due to one of available characteristics linear square or user definable multipoint max 20 points length The
12. 20 Input current mA Figure 6 1 Normal Lo CAL lt Hi CAL and inverted Lo CAL gt Hi CAL characteristic Square characteristic The normalized result is squared and further conversion is done as for linear characteristic Conversion is made accordingly with the expression W h2 x Hi CAL Lo CAL Lo CAL where W means the value returned in measurement register x O gt m ge fe N gt m Oo Oo 5s 55 oa ao Lo CAL Hi CAL 0 8 12 16 20 0 8 12 16 20 Input current mA Input current mA Figure 6 2 Normal Lo CAL lt Hi CAL and inverted Lo CAL gt Hi CAL characteristic 10 User manual for module with analogue inputs PMI 8S Square root characteristic The normalized result is rooted and further conversion is done as for linear characteristic Conversion is made accordingly with the expression W NI x Hi CAL Lo CAL Lo CAL where W means the value returned in measurement register fa Showed above expression is not valid when normalized result is negative It is 1 possible for 4 20 mode only In this case In lt 0 the returned result is equal Lo CAL mr see graphs below Hi CAL Lo CAL Returned value Returned value Hi CAL 8 12 16 20 0 4 8 12 16 20 Input current mA Input current mA Figure 6 3 Normal Lo CAL lt Hi CAL and inverted Lo CAL gt Hi CAL characteristic
13. BD SIMEX lt a division of BD SENSORS USER MANUAL for module with analogue inputs type PMI 8S firmware version 1 00 or higher current inputs PMI 8S P voltage inputs PMI 8S N Read the user s manual carefully before starting to use the unit Producer reserves the right to implement changes without prior notice 29 04 2009 V 1 06 User manual for module with analogue inputs PMI 8S CONTENTS 1 BASIC REQUIREMENTS AND USER SAFETY 2 1 42u2 0 chaws00004r 12000 naeh 3 2 GENERAL CHARACTERISTIES 2 2 an ee ea ee ie 3 3 TECHNICAE DATA nenne E eee oR ea neuere 4 4 DEVICE INSTALLATION rigsi R 5 AUN ACAIN EN T E EBEEBLEEELEBREEEESCERE 5 A2 CONNECTION ME THO inserere ee ee ee ee ee 5 da MAIN TE NANCE irae et ee ee ee eig 7 SE FRINCGIFLE OF OFERA TION cae asa se cee ssc E E 7 6 MEASURED VALUES CALCULATION nun ee ee es 9 6 1 ADDITIONAL CALCULATIONS USED CONVERSION CHARACTERISTIC 222222222222200 9 6 2 EXAMPLES OF CALCULA TIONS erinnere 12 7 THE MODBUS PROTOCOL HANDLING 2 u u u2 e ee 15 FL T OFRE TE x nenne ee E E 15 7 2 TRANSMISSION ERRORS DESCRIPTION u 17 7 3 EXAMPLES OF QUERY ANSWER FRAMES nee ee 17 Explanation of symbols used in the manual A This symbol denotes especially important guidelines concerning the installation and N operation of the device Not complying with the guidelines denoted by this symbol _ may cause an accident damage or equipment destruction
14. as stated must be disconnected and submitted for repairs at an authorized service centre 2 GENERAL CHARACTERISTICS Module allows measurement of 8 analog channels current or voltage depending on version and makes them accessible via RS 485 interface PMI 8S can be used as input block of scattered measurement and visualization systems Standard Modbus RTU functions can be used for changing module settings like address baud rate measurement ranges etc and read measurement results or identification data User manual for module with analogue inputs PMI 8S 3 TECHNICAL DATA Power supply voltage External fuse required Current consumption Number of independent inputs Inputs depending on version current or voltage Measurement accuracy Accepted prolonged inputs overload Galvanic isolation Communication interface Baud rate Number of modules in 1 network Data memory Protection level Housing type Housing dimensions L x W x D Operating temperature Storage temperature Humidity Altitude Screws tightening max torque Max connection leads diameter EMC 16 24 30 Voc T type max 1 A 55 mA typically 8 0 20 mA 4 20 mA 0 10 V 2 10 V 0 5 V 1 5 V 0 25 one digit 20 All inputs are galvanically isolated from module supply and RS 485 interface RS 485 8N1 Modbus RTU 1200 115200 bit sec maximum 128 non volatile memory EEPROM type IP 20 housing and connection clips
15. ces has default address FEh 21h No 209Ah Device identification code ID Baudrate 0 1200 baud 1 2400 baud 2 4800 baud 22h Yes 0 7 3 9600 baud 4 19200 baud 5 38400 baud 6 57600 baud 7 115200 baud TORET e Additional response delay 0 no additional delay a ME Se 5 200 characters delay Maximum delay between received frames 27h Yes 0 99 0 no delay checking 1 99 maximum delay expressed in seconds 15 User manual for module with analogue inputs PMI 8S Register Write Range Register description 28h 2Fh Channel 1 parameters block 30h 37h Channel 2 parameters block 38h 3Fh Channel 3 parameters block 40h 47h Channel 4 parameters block See below 48h AFh Channel 5 parameters block 50h 57h Channel 6 parameters block 58h 5Fh Channel 7 parameters block 60h 67h Channel 8 parameters block 4 The value of X coordinate of point no 1 of the user defined sgn Yes 999 1999 characteristic expressed in 0 1 The value of Y coordinate of point no 1 of the user defined Fun en characteristic no decimal point included 72h 95h Further pairs of X Y coordinates of points no 2 19 of i the user defined characteristic 4 The value of X coordinate of point no 20 of the user defined 36h Yes 999 1999 characteristic expressed in 0 1 4 The value of Y coordinate of point no 20 of the user defined 97h Yes 10000 10000
16. e unit please find user s manual warranty 4 2 CONNECTION METHOD Caution Installation should be conducted by qualified personnel During installation all available safety requirements should be considered The fitter is responsible for executing the installation according to this manual local safety and EMC regulations Wiring must meet appropriate standards and local regulations and laws In order to secure against accidental short circuit the connection cables must be terminated with appropriate insulated cable tips Tighten the clamping screws The recommended tightening torque is 0 5 Nm Loose screws can cause fire or defective operation Over tightening can lead to damaging the connections inside the units and breaking the thread In the case of the unit being fitted with separable clamps they should be inserted into appropriate connectors in the unit even if they are not used for any connections Unused clamps marked as n c must not be used for connecting any connecting cables e g as bridges because this can cause damage to the equipment or electric shock User manual for module with analogue inputs PMI 8S Due to possible significant interference in industrial installations appropriate measures assuring correct operation of the unit must be applied To avoid the unit of improper indications keep recommendations listed below Avoid common parallel leading of signal cables and transmission cab
17. esult so the returned value W 337 300 637 b in 25 mA and Ir 0 0938 W 216 C lin 20 5 mA and In 1 0313 W 1228 Example 4 The square characteristic Let the input mode 4 20 mA and parameters Lo CAL and Hi CAL equal to 300 and 1200 respectively The calculations will be done for there different input currents from example 2 a lin 10 mA and In 0 375 Accordingly to expression on page 10 for linear characteristic 0 375 x 1200 300 127 and next the Lo CAL value is added to the result so the returned value W 127 300 427 b lin 2 5 mA and In 0 0938 W 308 c lin 20 5 mA and In 1 0313 W 1257 Example 5 The square root characteristic Let the input mode 4 20 mA and parameters Lo CAL and Hi CAL equal to 300 and 1200 respectively The calculations will be done for there different input currents from example 2 a lin 10 mA and In 0 375 Accordingly to expression on page 11 for linear characteristic V0 375 x 1200 300 551 and next the Lo CAL value is added to the result so the returned value W 551 300 851 b lin 2 5 mA and In 0 0938 normalized result is negative so the returned value is equal to Lo CAL parameter W Lo CAL 300 c lin 20 5 mA and In 1 0313 W 1214 13 User manual for module with analogue inputs PMI 8S Example 6 The user defined characteristic Let the inpu
18. expansion of nominal range is defined by Lo r and Hi r parameters They determine the permissible range of input signal Figure 5 1 The permissible range allow user to exceed the nominal range of input signal If input signal exceeds the permissible range defined by Lo r and Hi r appropriate bit of status register register 09h will be set This bit signalise exceeding of permissible measurement range The Lo r parameter is important if input is set to 4 20 1 5 or 2 10 mode only and determines lower border of the permissible range If input is set to 0 20 0 5 or 0 10 mode then lower border of the permissible range is always 0 For example if input is set to 4 20 mode then lower border is calculated due to expression Imn 4MA 4mAx Lo r The Lo r value can be set from 0 to 99 9 User manual for module with analogue inputs PMI 8S Lo r 75 0 3 mA Hi r 5 0 1 mA N Pi N t nominal measurement range 4 20mA EA min 1 i permissible measurement range gt lt gt lt x se a A A measurement result is displayed as display regardless on nominal range exceeding display message Lo message Hi Figure 5 1 Example of definition of permissible range of input signal Lor and Hi r parameters 4 20 mode Parameter Hi r determines the upper border of the permissible range accordingly to the
19. les together with power supply cables and cables controlling induction loads e g contactors Such cables should cross at a right angle Contactor coils and induction loads should be equipped with anti interference protection systems e g RC type Use of screened signal cables is recommended Signal cable screens should be connected to the earthing only at one of the ends of the screened cable In the case of magnetically induced interference the use of twisted couples of signal cables so called spirals is recommended The spiral best if shielded must be used with RS 485 serial transmission connections In the case of interference from the power supply side the use of appropriate anti interference filters is recommended Bear in mind that the connection between the filter and the unit should be as short as possible and the metal housing of the filter must be connected to the earthing with largest possible surface The cables connected to the filter output must not run in parallel with cables with interference e g circuits controlling relays or contactors External powers supply must be connected to the module Uz Uz typically 24 Voc and two wires RS 485 A B communication interface Inputs are placed on bottom side of the module see Figure 4 1 power supply RS 485 power supply 24V DC SLAVE ground tN Uz A B Uz force address OxFF swich is available through this hole IN1 IN8 inputs ground
20. on modbus network FUNC Function code REG H L Starting address address of first register to read write Hi and Lo byte COUNT H L No of registers to read write Hi and Lo byte BYTEC Data byte count in answer frame DATA H L Data byte Hi and Lo byte CRC L H CRC error check Hi and Lo byte 17 User manual for module with analogue inputs PMI 8S 1 Read of the registers 01h 09h in one message example of reading a number of registries in one frame ADDR FUNC REG H L DATA CRC L H 01 03 00 01 00 09 D4 0C a The answer ADDR FUNC BYTEC DATA CRC L H o3 12 joo 96 Ec 7e o7 4 oo o0 oo 0 oo oo 00 00 00 oo os 00 ap 49 Chanel 1 Chanel 2 Chanel 3 Chanel 4 Chanel 5 Chanel 6 Chanel Chanel amp Status Interpretation of the answer Channels 1 2 3 results respectively 150 5000 2020 negative numbers U2 coded All other channels give 0 Status register signalizes overflow in channel 3 2 Read of device ID code ADDR FUNC REG H L COUNT H L CRC L H 01 03 00 21 00 01 D4 00 The answer ADDR FUNC BYTEC DATA H L CRC L H 01 03 02 20 9A 21 EF DATA identification code 209Ah 3 Change of the device address from 1 to 2 write to reg 20h ADDR FUNC REG H L DATA H L CRC L H 01 06 00 20 00 02 09 C1 DATAH 0 DATA L
21. returned as Channel Result when input current is equal to bottom border of the selected range 16 User manual for module with analogue inputs PMI 8S Relative Description address Write Range Parameter Hi CAL 4 Yes 10000 10000 This value is returned as Channel Result when input current is equal to upper border of the selected range Parameter Lo r expressed by 0 1 5 Yes 0 999 Percentage extension of measurement range below its bottom border Parameter Hi r expressed by 0 1 6 Yes 0 200 Percentage extension of measurement range over its upper border l It is possible to read up to 12 registers at once see example no 1 Qe Content of status register no 09h Bit no 15 8 7 0 function H8 H1 L8 L1 Bits H1 to H8 mean overflow of measurement range of particular channels Bits L1 to L8 mean underflow of measurement range of particular channels 7 2 TRANSMISSION ERRORS DESCRIPTION If an error occurs while write or read of single register then the device sends an error code according to Modbus RTU specifications Error codes 01h illegal function only functions 03h and O6h are available 02h illegal register address 03h illegal data value 7 3 EXAMPLES OF QUERY ANSWER FRAMES Examples apply for device with address 1 All values are represent hexadecimal Field description ADDR Device address
22. sing green LED indicator starts to flashes again Simultaneously with change of device address its baud rate is changed to 9600 bit sec Required transmission speed 1200 bit sec to 115200 bit sec can be set by write to register 22h After change of transmission speed the device sends the answer with new baud rate While installation of the new network it is recommended to readdress all devices using baud rate 9600 bit sec and next change speed of all devices simultaneously using BROADCAST query with address OOh 6 MEASURED VALUES CALCULATION For simplicity of examples it s assumed that current input is selected and all calculations are related to this input When voltage input is selected calculations are similar be sure of particular ranges and units The first step to compute the result of measure is the calculation of the normalized result it means result of 0 1 range To do it the begin of the input range 0 mA for 0 20 mA range and 4 mA for 4 20 mA range must be subtracted from measured value Next received result must be divided by the width of the input range it means 20 mA for 0 20 mA range and 16 mA for 4 20 mA range So normalized result can be expressed by expressions I inp 4 a a wd for 4 20mA_ range n 16 u I _ fe 5 0 S 20 i 4 i op n 50 0 foi 20mA range where linp Means input current in mA and In normalized result ve If measured value exceeds the nominal input range 0 20 mA or 4 20
23. t mode 4 20 mA and the user selected the 10 segment characteristic To do this it is necessary to enter X and Y coordinates of 11 points see LIST OF REGISTERS The calculations will be done for three different input currents from example 2 so in calculations some of the segments will be used only Let the following points will be given X1 00 0 Y1 10 0 X2 10 0 Y2 20 0 X6 30 0 Y6 30 0 X7 40 0 Y7 80 0 X10 90 0 Y10 900 0 X11 100 0 Y11 820 0 Additionally all other points must to be defined and stored in the device memory a lin 10 mA and In 0 375 The segment defined by X6 30 0 i X7 40 0 for this will be selected Accordingly to expressions given for user defined characteristic see page 11 X6 PL 30 Y6 PL 30 X7 PH 40 Y7 PH 80 and lp 0 3 the returned value Y PH Y PL 100 Y PL X PH X PL W I 1 0 375 0 3 x 8030 40 3 40 30 x 100 30 67 b lin 2 5 mA and In 0 0938 because of the normalized In value is lower than 0 the segment defined by X1 and X2 will be selected X1 PL 0 Y1 PL 10 X2 PH 10 Y2 PH 20 and lp 0 For these values the returned value W 1 b lin 20 5 mA and In 1 0313 because of the normalized In value is higher than 1 the segment defined by X10 and X11 will be selected and X10 PL 90 Y10 PL
Download Pdf Manuals
Related Search