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P-Series RS-422 cable

I'm trying use MODBUS protocols to communicate with my P-Series controller.  So I bought a tripp lite usb to rj45 adapter cable that is supposed to work with RS-422, but can't establish a link with the controller.   Does anyone have a recommendation for a usb to rj45 adapter cable that works with the P-series drive?


  • Not specifically, no.  However, there are several things that need to be configured correctly to make the connection work:

    • Baud rate.  The baud rate you set for your USB-RS422 converter must match what is set for your drive.  Same goes for the other settings, like stop bits and parity, although these cannot be changed on the drive.  To change baud rate, go to the General Config Setup page in Drive Support Tool (gear icon) and find the Baud Rate field near the bottom.
    • Pinout.  Could be that the system is just miswired.  Do you have a wiring diagram you can share?
    • Termination resistor.  Truth is, you can usually get away without this on a single-drive network with a short cable.  However, it is always a good idea to turn it on.

    Information about all three of these subjects can be found in the user guide on this page.

    As I read this now, you say that this Tripp Lite device has an RJ45 pinout on the RS422 side.  Thing is, I don't think there is a standard pinout for RS422 through RJ45.  It could be that the pinout is incompatible with the P Drive.  That is not necessarily a deal-breaker, but it would require you to reterminate the cable yourself.  RJ45 termination kits can be purchased online.  If you have access to university resources, someone in your electrical lab may be able to loan you one.  Barring that, see if IT has one they would be willing to loan you.