We've been using python 2.7 and pyserial to connect X30 and X31.

We can communicate successfully using RS232 at up to 115200 baud.

Switching to RS422 using switchserialmode on both ports and we get corruptions in the received data stream. Switch back to RS232 and it works.

We've tried two different cables. Both work using RS232 - both fail on RS422.

We're switching modes prior to running the software by using:

      switchserialmode /dev/ttyS2 rs422

      switchserialmode /dev/ttyS3 rs422

The cables are connected as follows:

     1 <--> 4

     2 <--> 3

     3 <--> 2

     4 <--> 1

     5 <--> 5

We've used the original example image 2.1.2 and the current image 2.1.3 with the same behaviour.

If we run a cable without pins 1 and 4 / 4 and 1 connected (RS232 three wire) then RS422 behaviour is similar to having them connected - which has made us question whether we are setting RS422 mode correctly on the interface (does the interface get reset by something that pyserial is doing) or that we have misunderstood how the cable should be wired.

Is there anybody out there who has managed to use RS422 successfully?

If so was there any patch required (I note that there have been details of a RS485 patch) and was siwtchserialmode used successfully?