BNC-2120 Installation Guide
Contents
1. The power indicator LED shown in Figure 1 lights If it does not light check the cable connections 3 Launch Measurement amp Automation Explorer MAX confirm that your DAQ device is recognized and configure your device settings Refer to the DAQ Getting Started Guide for more information 4 Connect signals to the BNC connectors and screw terminal block as described in the following sections nye Note With NI DAQm x National Instruments has revised its terminal names so they are easier to understand and more consistent among NI hardware and software products The revised terminal names used in this document are usually similar to the names they replace For a complete list of Traditional NI DAQ Legacy terminal names and their NI DAQmx equivalents refer to the Terminal Name Equivalents table in the NI DAQmx Help BNC 2120 Installation Guide 4 ni com 5 Test specific device functionality such as the ability to send and receive data with MAX test panels Refer to the DAQ Getting Started Guide for detailed information about running test panels in MAX When you have finished using the BNC 2120 power off any external signals connected to the BNC 2120 before you power off your computer Connecting Analog Input Signals You can use the analog input BNCs on the BNC 2120 in the following ways e Measure differential AI signals as described in the Connecting Differential Analog Input Signals section e Measure temperatu2. measure temperature on the BNC 2120 with the temperature reference and thermocouple connector To use the integrated circuit IC temperature reference on the BNC 2120 move the BNC Temp Ref switch above the AI 0 BNC to Temp Ref The integrated circuit IC temperature reference provides built in cold junction compensation CJC through software The IC sensor voltage is linearly proportional to the sensor temperature where C Volts x 100 The sensor is accurate to 1 5 C To use the thermocouple on the BNC 2120 move the BNC Thermocouple switch above the AI 1 BNC to Thermocouple You can connect any type of thermocouple with a two prong miniature or subminiature male connector to the thermocouple connector BNC 2120 Installation Guide 6 ni com For more information on thermocouples and CJC refer to the Developer Zone document Taking Thermocouple Temperature Measurements by going to ni com info and entering the info code rdtttm Measuring Resistance You can measure resistance with the analog input screw terminals on the BNC 2120 Figure 4 is a schematic representation of how the BNC 2120 measures resistance Screw BNC 2120 Terminals RES Al3 O Al GND User Resistor Al SENSE BESS Al 11 10 kQ 0 5 Ny Figure 4 Measuring Resistance on the BNC 2120 RES is internally connected to AI 3 and Vcc RES is internally connected to AI 11 There is also a 10 kQ resistor b
3. ni com environment rohs_china National Instruments Corporation 15 BNC 2120 Installation Guide National Instruments NI ni com and LabVIEW are trademarks of National Instruments Corporation Refer to the Terms of Use section on ni com 1legal for more information about National Instruments trademarks Other product and company names mentioned herein are trademarks or trade names of their respective companies For patents covering National Instruments products refer to the appropriate location Help Patents in your software the patents txt file on your CD or ni com patents 1999 2008 National Instruments Corporation All rights reserved 372123C 01 Feb08
4. to 4 4 Vp p Amplitude adjust cccceseseseseeseeseeeeteeees Through the Amplitude Adjust knob Comparison Triangle wave is approximately 2 times the sine wave output 4 4 V p maximum Output impedance ssiri 600 Q Drive capability Square Wave Vp p e Sine Triangle Wave Vp p 6 5 4 2 S 3 2 1 0 1M 10k 5k 2k 1k 560 Ohms Figure 7 Typical Maximum Voltages versus Load Impedances Timing Input Output Screw terminal Sernec 14 positions 28 16 AWG wire BNE COnNE COOP scissors inite rr EE 1 for PFI 0 AI START TRIG Protection DC max V Powered off iiss descisesecensiticatendein idiot 1 7V Powered OMniss sje0scse05225echdei eas veies haveresievseioetaxe 6 7 1 7 V Quadrature Encoder Screw terminal Sarsina as 2 Output signals PULSES siue ro EON 96 pulses revolution UP DN eo TAE N High for clockwise rotation low for counterclockwise rotation National Instruments Corporation 13 BNC 2120 Installation Guide Power Requirement 45 VDC CES 9 rissies aiian 200 mA sourced from the multifunction DAQ device Power available at 5 V screw terminal Multifunction DAQ device power less power consumed at 5 VDC 5 Physical DIMENSIONS 25st cies eeceee a atta 26 7 cm x 11 2 cm x 5 97 cm 10 5 in x 4 41 in x 2 35 in Weight c siren i enie r r nA 1 040 g 2 lb 4 7 oz VO connector sororeionnegranana sad 68 pin male SCSI II ty
5. 00 pin E Series device Cable s for DAQ device s as listed in Table 1 The E Series User Manual the M Series User Manual or the S Series User Manual BNC cables 28 16 AWG wire Wire strippers Flathead screwdriver Installing the BNC 2120 Figure 1 shows the front panel of the BNC 2120 You can use two BNC 2120 accessories with both connectors of NI 6224 6229 6254 6259 6284 6289 M Series devices 2 You cannot use the BNC 2120 with Connector 1 of NI 6225 6255 devices BNC 2120 Installation Guide 2 ni com ANALOG INPUTS Floating Source FS y NATIONAL Ground Ref P Source GS _ AIS RES TIMING I O INSTRUMENTS s N BNC 2120 PFI O P1 0 Quadrature Encoder 196 Pulses Rev PULSES UP DN PELI PLA PFI2 PI12 PFI3 P13 PRLA PIA PFI57P15 PFI 67 P1 6 PEI7 P17 PFI8 P20 PFI9 P21 PFLI2 P2 4 PFLI3 P2 5 PFI 14 P2 6 SOVGVSDSDODDOSAeg FUNCTION GENERATOR Frequency Selection USER DEFINED SIGNALS 0 1 10 kHz a DIGITAL O 1 100 kHz 13
6. 1000 kHz TTL Square Wave Lo HI Amplitude Adjust IDI C rt md d4hs l Frequency Adjust RES BNC Switch Al 3 Resistor Measurement Screw Terminals Thermocouple Input Connector Temperature Reference BNC Temp Ref Switch Al 0 BNC Thermocouple Switch Al 1 Analog Input BNC Connectors FS GS Switches bo NONA Analog Output BNC Connector Frequency Range Selection Switch Sine Triangle BNC Connector TTL Square Wave BNC Connector Sine Triangle Waveform Switch Frequency Adjust Knob Amplitude Adjust Knob Digital I O Screw Terminals Digital 1 O LEDs User Defined Screw Terminals User Defined BNC Connectors Timing I O Screw Terminals Quadrature Encoder Screw Terminals Quadrature Encoder Knob Timing I O BNC Connector Power Indicator LED National Instruments Corporation Figure 1 BNC 2120 Front Panel BNC 2120 Installation Guide To connect the BNC 2120 to your DAQ device complete the following steps Consult your computer or PXI PXI Express chassis user manual for specific instructions and warnings ay Note If you have not already installed your DAQ device refer to the DAQ Getting Started Guide for instructions UN Caution Do not connect the BNC 2120 to any device other than National Instruments E M S Series multifunction DAQ devices Doing so can damage the BNC 2120 the DAQ device or the host computer National Instr
7. NC connectors allow you to use a BNC connector for a digital I O or timing I O signal of your choice The USER 1 and USER 2 BNC connectors are routed internal to the BNC 2120 to the USER 1 and USER 2 screw terminals as shown in Figure 5 USER 1 BNC Internal A Connection DGND e USER 1 USER 2 BNC 12 _ USER 2 i A E Internal pe Connection D GND WV Figure 5 USER lt 1 2 gt BNC Connections Figure 5 shows an example of how to use the USER 1 and USER 2 BNCs To access the PFI 8 P2 0 CTR 0 SOURCE signal from a BNC connect USER 1 on the screw terminal block to PFI 8 P2 0 with a 28 16 AWG wire BNC 2120 Installation Guide 10 ni com TIMING I O Screw Terminal Block PFI 8 P2 0 PFI 9 P2 1 PFI 12 P2 4 USER 1 BNC BNC Cable D GND PFI 8 Signal Figure 6 Connecting PFI 8 to USER 1 BNC The designated space next to each USER lt 1 2 gt BNC is for marking or labeling signal names Connecting Digital 1 0 Signals Connect to the digital I O signals of your DAQ device to the digital I O screw terminals P0 lt 0 7 gt on the BNC 2120 You can individually configure each signal as an input or output D GND is available at the screw terminals to supply the reference for the DIO signals When connecting signals to the screw terminals use 28 16 AWG wire with the insulation stripped to 0 28 in 3 Note P0 6 and PO 7 can co
8. P1 5 Programmable Function Input channel 5 or Port 1 Digital Input Output channel 5 AO SAMP CLK AO Sample Clock Signal As an output this pin is the ao SampleClock signal A high to low edge on AO SAMP indicates that the AO primary group is being updated PFI 6 P1 6 Programmable Function Input channel 6 or Port 1 Digital Input Output channel 6 AO START TRIG AO Start Trigger Signal As an output this pin is the ao StartTrigger signal In timed AO sequences a low to high transition indicates the initiation of the waveform generation PFI 7 P1 7 Programmable Function Input channel 7 or Port 1 Digital Input Output channel 7 AI SAMP CLK AI Sample Clock Signal As an output this pin is the ai SampleClock signal This pin pulses once at the start of each AI sample in the interval sample A low to high transition indicates the start of the sample PFI 8 P2 0 Programmable Function Input channel 8 or Port 2 Digital Input Output channel 0 CTR 0 SOURCE Counter 0 Source Signal As an output this pin is the CtrOSource signal This signal reflects the actual source connected to the general purpose counter 0 PFI 9 P2 1 Programmable Function Input channel 9 or Port 2 Digital Input Output channel 1 CTR 0 GATE Counter 0 Gate Signal As an output this pin is the CtrOGate signal This signal reflects the actual gate signal connected to the general purpose counter 0 PFI 12 P2 4 Programmable Fu
9. a ttn Loe nce a heen 2 screw terminals Resistor Measurement range 00 eee eeeeteeeeees 100 Q to 1 MQ Resistor measurement error 0 0 eee eeeeeeteeeeeees lt 5 Screw terminals 04 541 2 3 2 s2 3 endevesrgensenessene stesso 4 positions 28 16 AWG wire Switches Floating source grounded source 4 8 BNC temperature reference IC 0 0 1 BNC thermocouple connector 1 BNC resistor screw terminals 0 0 1 Analog Output Field Connect on vissescssecceises cites nnr 2 BNC connectors Digital Input Output Screw terminals sis Acie ee 9 positions 28 16 AWG wire LED state indicators ccccccsccesssceesseeesseeesseeees 8 1 each for lines P0 lt 0 7 gt Protection DC max V Powered off 5 5 V Powered Offs cesses ccescecccehacesesicesedsdercestevecsteetases 10 5 V Drive AEE E E acon 0 6 V 8 mA 1 6 V 24 mA Voiron ian enre i n 4 4 V 8 mA 4 V 13 mA Function Generator SQUALE WAVE s cui cescsisiserssssesecsecsecsdonisetenesedesseonenstontons TTL compatible Frequency Tange naenin annn nsis 100 Hz to 1 MHz Frequency adjust 0 0 0 ceeeeeeeeseesceeceeeeeeeaeees Through the Frequency Adjust knob BNC 2120 Installation Guide 12 ni com Rige Ume enen sts cates A R 250 ns Fall time Sine triangle wave Frequency range 100 Hz to 1 MHz Frequency adjust s eseseeeseeeeeeeseeeeerseseseeseeee Through the Frequency Adjust knob Amplitude range sarsnogensss a 60 mV
10. e Setup Options directs you to pull down the File menu select the Page Setup item and select Options from the last dialog box This icon denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash When this symbol is marked on a product refer to the Read Me First Safety and Radio Frequency Interference document for information about precautions to take Bold text denotes items that you must select or click in the software such as menu items and dialog box options Bold text also denotes parameter names Italic text denotes variables emphasis a cross reference or an introduction to a key concept Italic text also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions What You Need to Get Started To set up and use your BNC 2120 accessory you need the following m m m CODODD m BNC 2120 accessory accessories BNC 2120 Installation Guide One of the following DAQ devices 68 pin E M S Series device with one or two I O connectors 1
11. ee INSTALLATION GUIDE BNC 2120 Connector Accessory for E M S Series Devices This installation guide describes how to install configure and use your BNC 2120 accessory with 68 pin or 100 pin E M S Series multifunction data acquisition DAQ devices This document also contains accessory specifications The BNC 2120 has the following features e Eight BNC connectors for analog input AI connection e Onboard temperature reference e Thermocouple connector e Resistor measurement screw terminals e Two BNC connectors for analog output AO connection e Screw terminals for digital I O DIO connection with state indicators e Screw terminals for timing I O TIO connection e Two user defined BNC connectors e A function generator with the following outputs Frequency adjustable TTL compatible square wave Frequency and amplitude adjustable sine wave or triangle wave e Quadrature encoder e A 68 pin I O connector that connects to multifunction DAQ devices e Can be used on a desktop or mounted on a DIN rail Contents CONVENIOS isic seien issart aniors i enan E EC ANE EEE AEEA Ea E eai SEIRENA ISL EE ES EATER EGAS EATE E SaaS EEES Eino 2 What Y u Need to Get Started osiisie ccicccecsseeiescuhevdoe Roti oats Hotes dbei basevi r EiS Ei Eeee 2 Installing the BNC 2120 airea a Ea A E AA TEENETE EER EEE EEEE EER 2 Connecting Analog Input Signals s scscscssssaisesdatecsseessstassvesseszcasssasevs obsobsvsaadee sees devlawsussvesueiv
12. er to the Using the Quadrature Encoder section for information about using these terminals PFI 1 P1 1 PFI 2 P1 2 Programmable Function Input channel 1 or Port 1 Digital Input Output channel 1 AI REF TRIG AI Reference Trigger Signal As an output this pin is the ai ReferenceTrigger signal In applications with pretrigger samples a low to high transition indicates the initiation of the post trigger samples AI Reference Trigger is not used in applications with posttrigger samples Programmable Function Input channel 2 or Port 1 Digital Input Output channel 2 AI CONV CLK AI Convert Clock Signal As an output this pin is the ai ConvertClock signal A high to low edge on AI CONV indicates that an A D conversion is occurring PFI 3 P1 3 Programmable Function Input channel 3 or Port 1 Digital Input Output channel 3 CTR 1 SOURCE Counter 1 Source Signal As an output this pin is the CtrlSource signal This signal reflects the actual source connected to the general purpose counter 1 BNC 2120 Installation Guide 8 ni com Table 2 BNC 2120 Timing 1 0 BNC Terminal Descriptions Continued BNC Terminal Description PFI 4 P1 4 Programmable Function Input channel 4 or Port 1 Digital Input Output channel 4 CTR 1 GATE Counter 1 Gate Signal As an output this pin is the Ctr1Gate signal This signal reflects the actual gate signal connected to the general purpose counter 1 PFI 5
13. etelavievonsiossed 5 Connecting Differential Analog Input Signals 0 ccc eeeceeeeseeeeeeeseeeeeeeeeseeeseevaceetseseeeesanaees 5 Measuring Floating Sigmals c cscecsssece cesssoscsnevassscoceonssstanczeccsestaeeaseassaesdevaeeseseednesss Coneonssnsoas 5 Measuring Ground Referenced Signals sssesssseeisssisiererrerrstnrnressrsrererersrnrsrnrtnrernesee 6 Measuring Temperatures corren EREE E T R 6 Measuring Resistance sssaaa tE sE E EE EEK A RE EE EAEE ERSEN REAS 7 Connecting Analog Output Signals isisessissrseri rinsio irienna iaa ai 7 Using the Function Generator 8 Connecting Timing VO Signals cs is is iidssscessisiscsseteisssasesssssavecsievecsa oaadeasivessxsauvesesssussvescobssaedoioctdeatesecs 8 Using the Quadrature Encoders cass sissies dutvies eepdeaveitavtnceseanese cies saved bordaiboabictsoddtbasavenaytvesy 10 Connecting User Defined Signals LO Connecting Digital I O Signals 11 SpeCifiGatloms siscsscstiscessts scosleases veces Saeck dadeheni sesscubdsechaassleaco seus EE R ET 11 Wi NATIONAL p INSTRUMENTS Conventions The following conventions are used in this document lt gt bold italic monospace Angle brackets that contain numbers separated by an ellipsis represent a range of values associated with a bit or signal name for example AO lt 3 0 gt The symbol leads you through nested menu items and dialog box options to a final action The sequence File Pag
14. etween AI 11 and AI GND When connecting signals to the screw terminals use 28 16 AWG wire with the insulation stripped to 0 28 in Complete the following steps to measure resistance 1 Move the RES BNC switch above the AI 3 BNC to the RES position 2 Configure your software to measure AI 3 and AI 11 in referenced single ended RSE mode 3 Connect the resistor to the RES and RES screw terminals You can measure resistors with values ranging from 100 Q to 1 MQ 4 Measure Vcc on AI 3 and the voltage drop across the internal 10 KQ resistor on AI 11 5 With these measurements calculate the resistor value using the following formula Vara Vari Resistor Value _ Var11 10 KQ Connecting Analog Output Signals Use the AO lt 0 1 gt BNC connectors on the BNC 2120 front panel to connect analog output signals to your DAQ device The number of connectors you use depends on your DAQ device and application Refer to your DAQ device documentation for information about the use of these signals 1 When using the BNC 2120 with Connector 1 of NI 6229 6259 6289 devices the AO lt 0 1 gt BNCs on the BNC 2120 map to the AO lt 2 3 gt channels on the M Series device National Instruments Corporation 7 BNC 2120 Installation Guide Using the Function Generator The BNC 2120 has a function generator that produces sine or triangle waveforms and TTL compatible square waveforms Use the switch below the Sine T
15. ing as follows e 2006 95 EC Low Voltage Directive safety e 89 336 EEC Electromagnetic Compatibility Directive EMC 3 Note Refer to the Declaration of Conformity DoC for this product for any additional regulatory compliance information To obtain the DoC for this product visit ni com certification search by model number or product line and click the appropriate link in the Certification column Environmental Management National Instruments is committed to designing and manufacturing products in an environmentally responsible manner NI recognizes that eliminating certain hazardous substances from our products is beneficial not only to the environment but also to NI customers For additional environmental information refer to the NI and the Environment Web page at ni com environment This page contains the environmental regulations and directives with which NI complies as well as other environmental information not included in this document Waste Electrical and Electronic Equipment WEEE Ds EU Customers At the end of their life cycle all products must be sent to a WEEE recycling center For more information about WEEE recycling centers and National Instruments WEEE initiatives visit ni com environment weee htm BAe Risks BEA CHE RoHS Oe PARA National Instruments 4AF E E FAR Ar EO A Se a ROHS KF National Instruments FE ROHS AAEM WS ni com environment rohs_china For information about China RoHS compliance go to
16. nction Input channel 12 or Port 2 Digital Input Output channel 4 CTR 0 OUT Counter 0 Output Signal As an input this pin can be used to route signals directly to the RTSI bus As an output this pin emits the CtrOInternalOutput signal PFI 13 P2 5 Programmable Function Input channel 13 or Port 2 Digital Input Output channel 5 CTR 1 OUT Counter 1 Output Signal As an input this pin can be used to route signals directly to the RTSI bus As an output this pin emits the Ctr1InternalOutput signal PFI 14 P2 6 Programmable Function Input channel 14 or Port 2 Digital Input Output channel 6 FREQ OUT Frequency Output This output is from the frequency generator 5 V 5 V Power These terminals are fused on the DAQ device and are self resetting The current available depends on the product to which it is connected D GND Digital Ground This terminal supplies the reference for the digital signals at the T O connector as well as the 5 VDC supply National Instruments Corporation 9 BNC 2120 Installation Guide Using the Quadrature Encoder The BNC 2120 contains a mechanical quadrature encoder circuit that produces 96 pulses per encoder revolution Two outputs PULSES and UP DN are at the screw terminals located below the quadrature encoder knob PULSES outputs a pulse train generated by rotating the encoder shaft It provides four pulses per one mechanical click of the encoder UP DN outp
17. ntrol the up down signal of general purpose counters 0 and 1 respectively Refer to the Using the Quadrature Encoder section for more information about using the P0 6 and PO 7 terminals with the quadrature encoder The LEDs next to each screw terminal indicate the state of each digital line as listed in Table 3 Table 3 Digital I O LEDs Digital O LED Digital Port State Lit The port is either pulled high or driven high Not lit The port is either pulled low or driven low Specifications This section lists the specifications of the BNC 2120 These specifications are typical at 25 C unless otherwise specified 3 Note Refer to your DAQ device documentation for specifications about analog input analog output trigger counter and digital and timing I O signals National Instruments Corporation 11 BNC 2120 Installation Guide Analog Input Number of channels default cccececeeseeeeees 8 differential Field connections default ccceceeseeseeseeeees 8 BNC connectors POLE CHOM sss 52 4550 ven ccecedetedncaaceneens a e E kaina No additional protection provided Consult your DAQ device specifications Optional inputs Temperature sensor Thermocouple Resistor measurement requires RSE configuration Optional connections Thermocouple 0 0 cceessceeseeeeeeeeeeeeeeeees Uncompensated miniature connector mates with 2 prong miniature or subminiature connector RESIStOD 3 08 ii
18. pe BNC COmMECUOIS 5 055s0sssssscsssscecesssnssnssssssessessasnssvaees 15 Screw terminal plugs cece eseeeeseeeeeeeeeeees 31 Environment Operating temperature eee eect eteeeeteeeeees 0 to 50 C Storage temperature oe eee eset eee eeeeeeeee 55 to 125 C Relative humidity 0 ce eeeeeeeeeeeeeeeeneeeetees 5 to 90 noncondensing Pollution Degree indoor use only eseeeeeees 2 Maximum altitude ccccccccccccssccesseeesseeeseeeees 2 000 m Safety 3 This product is designed to meet the requirements of the following standards of safety for electrical equipment for measurement control and laboratory use e IEC 61010 1 EN 61010 1 e UL61010 1 CSA 61010 1 Note For UL and other safety certifications refer to the product label or visit ni com certification search by model number or product line and click the appropriate link in the Certification column Electromagnetic Compatibility 3 This product is designed to meet the requirements of the following standards of EMC for electrical equipment for measurement control and laboratory use e EN 61326 EMC requirements Minimum Immunity EN 55011 Emissions Group 1 Class A CE C Tick ICES and FCC Part 15 Emissions Class A Note For EMC compliance operate this device with shielded cables BNC 2120 Installation Guide 14 ni com CE Compliance This product meets the essential requirements of applicable European Directives as amended for CE mark
19. re as described in the Measuring Temperature section e Measure resistance as described in the Measuring Resistance section Connecting Differential Analog Input Signals Use the BNC 2120 BNC connectors on the front panel to connect AI lt 0 7 gt signals to your DAQ device The BNC 2120 is only intended for differential analog input signals The number of connectors you use depends on your DAQ device and application Complete the following steps to measure a differential DIFF analog input signal 1 Connect the BNC cable to one of the AI lt 0 7 gt BNC connectors on the front panel 2 If you are using AI 0 move the BNC Temp Ref switch to the BNC position If you are using AI 1 move the BNC Thermocouple switch to the BNC position If you are using AI 3 move the RES BNC switch to the BNC position 3 Configure your software to measure the channel differentially 4 Move the FS GS switch to the applicable position depending on whether you are measuring a floating source FS or ground referenced source GS analog input signal Refer to the Measuring Floating Signals and Measuring Ground Referenced Signals sections for more information about these signal sources Measuring Floating Signals To measure floating signal sources move the corresponding switch below the BNC connector to the FS position In the floating source switch position the DAQ device s amplifier negative terminal connects to ground through a 4 99 kQ resistor as
20. riangle BNC to select a sine wave or triangle wave output for the connector A TTL compatible square wave is always present at the TTL Square Wave BNC To adjust the frequency of the function generator select your frequency range using the Frequency Selection switch You can select 0 1 10 kHz 1 100 kHz or 13 1000 kHz The Frequency Adjust knob adjusts the frequency within the preselected range for the sine or triangle wave and the TTL square wave outputs The Amplitude Adjust knob adjusts the amplitude of the sine or triangle wave output up to 4 4 Vp p Connecting Timing 1 0 Signals Connect the timing I O signals of your DAQ device to the PFI 0 P1 0 AI START TRIG BNC or the timing I O screw terminals on the BNC 2120 When connecting signals to the screw terminals use 28 16 AWG wire with the insulation stripped to 0 28 in Table 2 describes the timing I O BNC and terminal signals on the BNC 2120 Table 2 BNC 2120 Timing 1 0 BNC Terminal Descriptions BNC Terminal Description PFI 0 P1 0 Programmable Function Input channel 0 or Port 1 Digital Input Output channel 0 AI START TRIG AI Start Trigger Signal As an output this pin is the ai StartTrigger signal In post trigger DAQ sequences a low to high transition indicates the initiation of the acquisition sequence In applications with pre trigger samples a low to high transition indicates the initiation of the pre trigger samples PULSES UP DN Ref
21. shown in Figure 2 Refer to your DAQ device documentation for more information about measuring floating signals 1 When using the BNC 2120 with Connector 1 of NI 6224 6229 6254 6259 6284 6289 devices the AI lt 0 7 gt BNCs on the BNC 2120 map to the AI lt 16 23 gt channels on the M Series device National Instruments Corporation 5 BNC 2120 Installation Guide DAQ Device Signal x 2 Seuice an B NC 2120 Ea Differential Input Mode o oe i FS k d i 0 1 uF ES Mode 1 4 99 kQ Figure 2 Measuring a Floating Signal Source Measuring Ground Referenced Signals To measure ground referenced signals move the switch below the BNC connector for the AI channel you are using to the GS position Using the ground referenced source switch position avoids ground loops as shown in Figure 3 Refer to your DAQ device documentation for more information about measuring ground referenced signals Signal DAQ Device Source ___ PNG 2120 E plana gt 4 i i GS i 0 i uF GS Mode i o T i no Fh GND 4 99 kQ i 1 Figure 3 Measuring a Ground Referenced Signal Source AI GND and AI SENSE signals are located at the analog input screw terminals of the BNC 2120 When connecting signals to the screw terminals use 28 16 AWG wire with the insulation stripped to 0 28 in Measuring Temperature You can
22. uments is not liable for damage resulting from these connections 1 Place the BNC 2120 near the host computer or PXI PXI Express chassis or use the optional DIN Rail Mounting kit for UMI FLEX 6 and BNC boxes part number 777972 01 which you can order from National Instruments at ni com UN Caution Do not connect input voltages greater than 42 4 V 60 VDC to the BNC 2120 The BNC 2120 is not designed for any input voltages greater than 42 4 V 60 VDC even if a user installed voltage divider reduces the voltage to within the input range of the DAQ device Input voltages greater than 42 4 V 60 VDC can damage the BNC 2120 all devices connected to it and the host computer Overvoltage can also cause an electric shock hazard for the operator National Instruments is not liable for damage or injury resulting from such misuse 2 Connect the BNC 2120 to the DAQ device using the appropriate cable for your DAQ device as listed in Table 1 Table 1 BNC 2120 Cabling Options Number of Pins DAQ Device Recommended Cable s 68 pin DAQCard E Series SHC68 68 EPM or RC68 68 NI PCI PCle PXI PXIe M Series NI 6143 S Series PCI PXI E Series SH68 68 EPM or R6868 USB Mass Termination M Series NI 611x 612x 613x S Series 100 pin PCI PXI E Series SH1006868 You cannot connect the BNC 2120 to Connector 1 of NI 6225 6255 devices t Do not use the R6868 cable with NI 6115 6120 S Series devices use only the SH68 68 EPM cable
23. uts a high or a low signal indicating rotation direction When the direction is counterclockwise UP DN is low When the direction is clockwise UP DN is high To use the quadrature encoder with counter 0 of the DAQ device connect the PULSES terminal to PFI 8 and connect the UP DN terminal to the P0 6 digital I O terminal the up down pin of counter 0 To use the quadrature encoder with counter 1 connect the PULSES terminal to PFI 3 and connect the UP DN terminal to the P0 7 digital I O terminal the up down pin of counter 1 Refer to Table 2 for more information about PFI 3 and PFI 8 Refer to the Connecting Digital I O Signals section for more information about the digital I O terminals and LEDs You can use the Count Digital Events VI from the LabVIEW Example Finder Hardware Input and Output DAQmx Counter Measurements Count Digital Events with the BNC 2120 quadrature encoder After opening the VI select Externally Controlled in the Count Direction control The VI retrieves the count from the counter You can convert the count into total degrees rotated using the following formula Total Degrees Rotated PULSES x 3 75 pulse where 3 75 pulse 360 96 pulses Calculate the number of revolutions and remaining degrees by dividing the total degrees rotated by 360 The calculated quotient is equal to the number of revolutions and the remainder is equal to the remaining degrees Connecting User Defined Signals The USER 1 and USER 2 B
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