OK great. I did some more testing and found a reason for the second item that displays incorrect data when I connect all devices to the 172.16.0.3 Ip address. If you look at the screenshot "ID error" you will see the driver settings in the upper right corner set to ID 245. There is in fact only one device that is ID 1. You can see modscan reading data in the bottom right which is set to ID 1. Modscan data matches the data seen by the BasicLabels on the left. I does not matter what ID I use, i get the same data returned. So it looks like the AdvHMI modbus driver is not using the device ID to distinguish devices.
I think you are on to something. I checked the UnitID and it never passed through to the packet, so every packet used an ID of 1. The Modbus simulator that I am using does not care about the UnitID, no matter what it gets passed, it will respond with data.
