ISOTCP Gateway Destination node

Question

We've noticed that the setting MPI/Profibus Gateway, on the eWON IOserver S73&400 tab, seems never be used.
It's default address is 2, but when changed to an unused MPI networkaddress, we are still able to go online with whatever PLC we want onMPI.

So my question is: when do you actually need this this setting, can you provide us with a case or situation where this setting must be entered/used?

Answer

Effectively, the ISOTCP protocol can be used in several ways, with or without a MPI node.
The "MPI Gateway" parameter is used only if the ISOTCP request doesn't specify the final MPI node.

Looking into the Reference Guide, you see that we show you 2 syntax examples of ISOTCP addressing.

The second example uses 4 parameters and the last one is MPI node address.
In this case, if another eWON receives this request, it will use the MPI node address of the request (and not the MPI node encoded in the IOServer).

At the opposite, using the first request example (with 2 params), as there is no final MPI node address, the ISOTCP request will be forwarded to the encoded MPI Gateway Node Address.

Note: The use of a short or a long ISOTCP request is dependant of the software used.