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What wire colors are used for RS-485 on a SeaI/O module?
Reference Number: AA-00522 Views: 6930 Created: 11/30/2011 06:28 pm Last Updated: 09/02/2016 05:29 pm 0 Rating/ Voters


We assume that you want to use a standard (CAT5/6 EIA/TIA-568B) Ethernet patch cable to connect to the RJ45 pass-through connector on the side of the SeaI/O module, due to their low cost, wide availability and various lengths.

If you are connecting a SeaI/O module to another RS-485 device, plug one end of the patch cable into the RJ45 pass-through connector on the side of the SeaI/O module. Cut off the RJ45 connector on the other end of the cable and connect the following wires to your RS-485 device:

  • Blue is RS-485 Data + (Data B)
  • White/Blue is RS-485 Data - (Data A)
  • Both Brown and White/Brown are Common (Signal Ground)

Note: If you are connecting two SeaI/O modules together, you can simply connect them together using a standard Ethernet patch cable. Do not use an Ethernet crossover cable, else you will short the power and ground wires.


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