Modicon Communication

I seem to be having issues with communication from RTU to SCADA. We are using a Modicon Micro 612. Just looking for basic troubleshooting tips for possible communication issues. I've been through the entire PLC programming and nothing seems to stick out. Need help.

Break it down first. You didn't give a lot to go on so my advice is similarly disorganized.

What do you know about the physical setup? Which port? What's on the other side of the PLC? Which one is the master/slave? Is it intermittent issue, is it limited to certain register vs all of them?

There are tools you can download for free, the 1st hit on google with "modbus slave simulator" is decent. Install it on your PC to make it the slave and see if the master device is functioning properly then go from there.

I should add that typically in a SCADA environment, the RTU is usually the master and the PLC is the slave but it doesn't have to be that way.

Thank you for that, I'll try to specify a little more.
Running well pumps that get monitored through the PLC.
So:
Pump -> PLC -> RTU -> SCADA at Host PC.

Using COMM2 as information source. This is not an intermittent issue. I was thrown into another persons mistakes so I am attempting to gather all info that I can.

Is there required to be a XMIT block in order for data to be transmitted? There are multiple Radio XFER blocks but not an XMIT.