Help with Twidos and GE MDS Communications

[abcoll]

Has anyone ever successfully gotten a Twido PLC to communicate over a GE MDS 4710 radio? The native port on the Twido is rs 485 which won’t work (to my knowledge). I added an rs232 port and I still cannot get communications to or from the master station. I’ve tried everything I can think of (custom cables, settings, etc.) Will the newer MDS SD4 radios work? The manual says the comm 2 port supports rs485.
I am using 9600 baud, 8,n,1.
I’m stuck with Modicon based PLC’s. Our Micro’s, Compacts and Quantums all work great with the MDS radios. The Twidos have me stumped (Tech support too).
Thanks!

 

[Lare]

Native port is rs485, but on default it is on programming mode.
For modbus mode you have to connect DPT pin to 0VDC on Minidin8 connector. After that port uses parameters what you have configured on program.

http://www.plctalk.net/qanda/showthread.php?t=67618

 

[abcoll]

Thanks Lare. I read the referenced post. Do you think what you suggested will work with the devices I'm using? I've attached images of the parameters. Do I need to use the rs232 module or just the native rs485? Thank you very much.

 

[Lare]

I have used different radios, but it should work on both rs232/RS485 if cabling and com-parameters are correct.

On testing it is easier if you use optional communication module (rs232 or RS485), because you can connect you laptop now also to PLC.

You said that you have succesfully used these radios with modicon based PLCs. Are they RS232 or RS485? Twido should also work with same parameters, only cabling differs little bit.

BTW, there is also RS485 module for twido, with it you need connect only RS485 A and B wires to radio.

 

[I is a noob]

X710 radios are on a licensed band of the range they are on. Do you understand the. Need to swap frequency on a point to point to make them work?

 

[abcoll]

We are using a licensed single frequency for both transmit and receive. I'm not sure what you mean.

 

[I is a noob]

You said you have not established comms to the master station, correct? Is it a point to point oe multiple address system? In a point to point if you transmit hi on one you have to receive hi on the other end. On a MAS the remote and polling remote are setup the same way and you master station(repeater) has the TX & RX frequencies swapped. If the Radio system is correct the remote radio connected to the PLC should have the DCD light lit and show have the RX lights up when a poll is initiated.