Micrologix 1100 series B- Modbus RTU Master

-Channel 0 as the modbus master port
-8 slaves (Yaskawa VFD's) on a RS-485 multi-drop network
-I can talk to the slaves (Yaskawa VFD's) through MD Bus by acting as the master ( modbus testing software ) so I know the network is good and the converter.
-The 2 wire RS-485 wires go into a RS-485 to RS-232 converter then into the PLC (CH 0).
-I have the master message instruction set on a 5 second timer and have the instruction set properly with the correct slave address, and modbus holding registers
-I have changed the CH 0 comm config (ie. No handshaking, rs 485, etc)

-The message instruction comes with an error "message time out" and no values show up in the registers I assigned in the message instruction?

What am I missing?

Thanks

Why are you converting to RS-232 to connect to the PLC? CH0 of the ML1100 supports RS-485 (use a 1763-NC01 and you have easy access terminals to wire directly to your 2-wire network)

Rob

I converted to RS-232 because I don't have this cable you speak of, all I have is this converter.
What exactly does this 1763-NC01 Cable do? I can't find any helpful documentation on it.

It's just a more convenient way of accessing the 8-pin mini din socket...

http://static.shop033.com/resources/F9/1000185/picture/50/30948176.jpg

Here is the pin-out of the 1763-NC01 cable.

If you are not going to use the above cable then under protocol control/control line just use "No Handshaking without the (485 Network) with your converter.