MSTR READ Modicon

Hello,

I have a 140-CPU-534 14 Modicon processor. I would like to READ a register from a SO2 analyser.

Do I need an Ethernet card or can I directly use the processor port for the READ function.

In the TCP/IP instruction help it is written the following for the register that must be configured:

4XXXX+4 Quantum slot adress of the network adapter module.

Looking at the part # for the CPU you supplied it doesnt support Modbus TCP onboard, only MB+ and Modbus RTU.
Now I'm assuming you have an NOE card in there to give you Modbus TCP.

I am a little surprised that an S02 analyser actually talks Modbus TCP as most of them are Modbus RTU. Assuming the analyser does talk TCP:

The register in the MSTR config block you mentioned is for the card # in the rack, which can be found in the IO config. Its so the CPU knows which port to send the message request from.

Modicon MSTR blocks are a bit of a PITA to get working but once you get one working its pretty straightforward.