Computer Interfacing
Discussions about interfacing and electronics

RS-422 Distribution

Running data to a remote area


       Computer Interfacing Forum Index -> RS422 and RS485
Author Message

May 07, 2010 1:53 am

Hello all,

I'm stuck. I need to run a RS-422 signal approx. 500ft and then split it to be distributed to 4 laptop workstations.

My initial thoughts are to convert the signal to ethernet and run STP to a 5 port ethernet switch. My only concerns are that I won't be able to utilize the data at the laptops in an ethernet format.

Does anyone have any suggestions?

Thanks. Smile

May 13, 2010 6:06 am

It isn't clear if you are starting with ethernet or wish to end up with ethernet, or if in fact it's only 422 you want at both ends. If it is the latter, ethernet isn't going to help you much as it has a general run length restriction of 100m (though it might work at you distance if you are lucky). If it is the splitting that you are worried about then ethernet isn't going to solve all of your problems. RS 485 is really the choice for multidropping in the way you describe, however, splitting RS 422 to up to 10 devices I think is possible, but the devices at the split end must be listen only and not need to reply. If they need to reply to messages, then you will need to go to RS 422. Can you give us any more details and we may be able to help more.
New User

Joined: 11 May 2010
Posts: 2

May 14, 2010 10:13 pm

Thanks for replying. Like I stated before, I need to send data out to 4 different laptops from one RS-422 source. No return data is required, so I only need one pair of wires. Is it ok to use a terminal board to daisy chain this signal into 4 outputs? If so, I think that's going to be the best course of action. OK, here's what I plan to do:
1. Run source TX pair to TB approx. 500 ft away.
2. Daisy chain TX pair at a TB to create 4 outputs.
3. Run each output approx. 20-30 ft to RS-422 to USB serial adapters.
4. Configure port emulation software and begin processing data.

My final question is, WILL THIS WORK?

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