The hardware is not Opto 22 modbus, but our own. To be honest, I do not know the name of the actual manufacture, but I am reading from the registers just fine.
Yes, we are running in Softpac; the charts are written in mostly opto-script in PAC Control Professional, R9.6d.
The goal is to read from Modbus tcp, perform calculations if needed, and then plug them in to our PID loop. Then with the PID results, update Modbus tcp registers with any new values as appropriate.
The chart you posted looks very promising!