Instruction/ maintenance manual of the product RS485 National Instruments
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OPERATING INSTRUCTIONS AND S PECIFICATIONS NI 9871 4-Port, RS485/RS42 2 Serial Modu le.
NI 9871 Operating Instructions 2 ni.com This document describes how to use the National Instruments 9871 and includes specif icat ions and pin assignments for the NI 9871. Vi s i t ni.com/info and enter rdsoftwareversion to determine which software you need for the modules you are using.
© National Instruments Corp. 3 NI 9871 Operating Instructions Safety Guidelines fo r Hazardous Loca tions The NI 9871 is suitable for use in Cl ass I, Division 2, Groups A, B, C, D, T4 hazardous locations; Clas s I, Zone 2, AEx nA II T4 and Ex nA II T4 hazardous locations ; and nonhazardous locations only .
NI 9871 Operating Instructions 4 ni.com Caution For Zone 2 applications, install a protection device between the RS485/RS 422 signal cables and the NI 9871 RJ-50 jacks (p orts 1– 4). The device must prev ent the RS485/RS422 signal-to -signal or signal-to-COM voltage from ex ceeding 23 V if there is a transient overv oltage condition.
© National Instruments Corp. 5 NI 9871 Operating Instructions Special Conditions fo r Marine Appli cations Some modules are Lloyd’ s Register (LR) T ype Approved for marine applications.
NI 9871 Operating Instructions 6 ni.com Wiring the NI 9871 The NI 9871 has four RJ-50 recep t acles that prov ide connections for four RS485/RS422 de vices.
© National Instruments Corp. 7 NI 9871 Operating Instructions The cables included with your kit con vert the RJ-50 pinout to the standard NI pinout, as shown in T able 2.
NI 9871 Operating Instructions 8 ni.com Y ou must connect an external po wer supply to the NI 9871. This power supply p rovides the po wer for the RS485/RS422 transceiv ers on th e module. Y ou can use the included female four-position pigtail to connect to an e xternal vo ltage source.
© National Instruments Corp. 9 NI 9871 Operating Instructions Figure 2 shows the method of po wer connection to the NI 9871 module. Attach an isolated power supply to the V sup and C OM terminals using the included pigtail.
NI 9871 Operating Instructions 10 ni.com additional module. Ensure that the power supply can handle maximum power requirements for all modules connected.
© National Instruments Corp. 11 NI 9871 Operating Instructions RS485 Bus T opology and T ermi nation Refer to Figure 4 and Fig ure 5 for an o vervie w of 4-wire and 2-wire RS485 bus topol ogies and termination. Figure 4. 4-Wir e Full-Dupl ex Multidrop Netw ork Using T erminating Resistors Figure 5.
NI 9871 Operating Instructions 12 ni.com RS485 T ransceiver Control Refer to T able 3 for a listing of TX and RX enable conditions for the dif ferent RS485 transcei ver contro l modes. NI 9871 Hardware Over view The NI 9871 has four independent RS48 5/RS422 ports that are isolated from the other modules in the system.
© National Instruments Corp. 13 NI 9871 Operating Instructions Sleep Mode (CompactRIO Only) Y ou can enable sleep mode fo r the CompactRIO system in software. In sleep mode, the syst em consumes less power and may dissipate less heat. T ypically , when a system is in sleep mode, you cannot communicate with th e modules.
NI 9871 Operating Instructions 14 ni.com Note Contact NI for Bellcore MTBF specifications at other temperatures or for MIL-HDBK -217F specifications. Power Requirements Power consumption from chassis Active mode ............ ........... ........ 0.5 W max Sleep mode .
© National Instruments Corp. 15 NI 9871 Operating Instructions Safety Maximum Voltage 1 Connect only v oltages that are within these limits. RS485/RS422 Port-to-COM ........ ..... –8 to +13 VDC max, Measurement Category I V SUP -to-COM ............
NI 9871 Operating Instructions 16 ni.com Isolation Voltages Port-to-earth ground W ithstand............... ......... ............ 1000 V rms , ver ifie d by a dielectric withstand test, 5 s Continuous .......... ........... ......... ... 60 VDC, Measurement Category I Hazardous Locations U.
© National Instruments Corp. 17 NI 9871 Operating Instructions Safety Standards The NI 9871 is designed to meet the requirements of the following standards of safety for electric al equipment for mea.
NI 9871 Operating Instructions 18 ni.com Note For the standards applied to assess the EMC of this product, refer to the Online Product Certification section.
© National Instruments Corp. 19 NI 9871 Operating Instructions Shock and Vibration T o meet these spec ifications, you must panel mou nt the CompactRIO system . Operating vibration, random (IEC 60068-2-64) ... ............. 5 g rms , 10 to 500 Hz Operating shock (IEC 60068-2-27).
NI 9871 Operating Instructions 20 ni.com Operating humidity ............. ........... ... 10 to 90% RH, noncondensing Storage humid ity ........ ........... ........... . 5 to 95% RH, noncondensing Maximum altitude.......... ......... .......... 2,000 m Pollution Degree (IEC 60664) .
© National Instruments Corp. 21 NI 9871 Operating Instructions Waste Electrical and Electronic Equipment (WEEE) EU Customers At the end of their lif e cycle, all products must be sent to a WEEE re c ycling center . For more information about WEEE recy cling centers and National Instruments WEEE initi ativ es, visi t ni.
NI 9871 Operating Instructions 22 ni.com Where to Go for Support The National Instruments W eb site is your complete resource for technical support. At ni.com/support you ha ve access to ev erything from troubleshooting and application de velopment self-help resources to emai l and phone assistance from NI Application Engineers.
© National Instruments Corp. 23 NI 9871 Operating Instructions K orea 82 02 3451 3400, Lebanon 961 (0) 1 33 28 28, Malaysia 1800 887710, Mexico 0 1 800 010 0793, Netherlands 31 (0) 348 433 466, New Z.
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An important point after buying a device National Instruments RS485 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought National Instruments RS485 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data National Instruments RS485 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, National Instruments RS485 you will learn all the available features of the product, as well as information on its operation. The information that you get National Instruments RS485 will certainly help you make a decision on the purchase.
If you already are a holder of National Instruments RS485, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime National Instruments RS485.
However, one of the most important roles played by the user manual is to help in solving problems with National Instruments RS485. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device National Instruments RS485 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
