Hi,
We have a M91-2-T1 that we haven't used for a while, and have just got it out again recently. I am trying to communicate with the PLC via RS232, but cannot communicate with the PLC. I am using:
USB to serial cable (Prolific, driver version 3.3.10.140), connected to;
DB9-RJ11 cable which we made according to the pin assignments in the U90 software manual (we also have another one with the RxD/TxD reversed because we thought we had the two around the wrong way)
I also tried using an older computer which has a RS232 port, and no luck there either, so that ruled out the problem of the USB to serial cable.
I have checked the COM port and settings (reset everything back to default), and they all seem fine. Is there a way I can test if the connections are correct by say, use HyperTerminal to send commands to the PLC, or is there any way I can find out what the problem might be?
Many thanks,
Danny