OK, I'm getting there, but am having trouble getting the PLC to talk to Mach, I think mainly because I'm confused about terminology. I have input FROM the PLC to Mach working but activating input auto-polling and setting it to "coils" (whatever that means :-)) In the PLC the inputs are called X and the address starts at hex 0000, so that is where I started the addressing in mach, seems to work fine, I told mach to look for Y home on port 0, pin 0 and if I activate the first input on the PLC the DRO lights up in Mach, everything is OK-Dokey.
The other way is where I am confused. The PLC outputs are labeled Y, but I don't think that is what I want. There is also a "thing" in the PLC called "C" which seem to be internal registers and I figured they would be what I need to write to, as they are the only other thing that seems to make sense. Their Modbus addresses start at 4000 HEX. If I enter 4000 hex into Mach it says that is an invalid address depending on where it is set. I've tried what seems like every combo of Holding, Coils, Input, and Discrete in the test page and while some seem to write values into the PLC somewhere, they don;t seem to change the "C" state....
Does that make any sense :-)? Thanks so much for all the help so-far, I appreciate it!
Dustin