How Ignition differentiate tags created from PLC with same registers?

Hello guys,

I want to add 2 new same PLC’s to our plant, and they are both same model.

The first step is as I read to add the devices in Ignition Gateway. But my question is how Ignition can differentiate the tags from tempreture created for these 2 locations with same PLC and same tags?

- screenshot from Gateway
- screenshot from Ignition designer

Thank you!

In the OPC Item Path, the beginning part in square brackets must name the device. When using UDT parameters as shown, the parameter IdPT must be either 411 or 413 to yield a proper device name. And thereby select which PLC is the target.

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I now understand the part with IdPT, it is show in the parameters list of the UDT, but also AdresaModbus is shown in the parameters list, but I notice that the address of the parameter is 1 for all the UDT’s. (see screenshots bellow)

Is that normal? What kind of address I need to put in the parameters list for the AdresaModbus exactly?

Thank you!

It depends on the device. When using serial Modbus, that allows you to address different nodes on the same link. With Modbus TCP, it is typically 0 or 1. With Modbus TCP to Modbus serial gateways, the address is typically passed through.

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Thank you very much for your explanation!