Modicon M340 Modbus TCP

[arun_mallah]

Hi,
I am trying to communicate modicon M340 PLC with an Schneider T200 Remote main unit controller over modbus TCP. the PLC has got in built Ethernet port. the modbus register I would like to read has address 341 Hex. I am bit confused how I am gonna used the READ_VAR instruction to read this register from T200 unit. Please let me know it's bit urgent
thanks
-Arun

 

[tragically1969]

Which part are you confused about ?

You will need to use ADDM to pass the address of the slave as a string into the READ_VAR, after that its a case of telling it what you want to read from where and where to put the data once its received (this has to be into an array of INT)

The READ_VAR command is very well documented in the help files within Unity, have you checked those out ?

 

[robertkjonesjr]

If you have an NOE or a NOC device, you could use the IOScanner serivce which usually makes things MUCH easier.

 

[arun_mallah]

thanks

Actually, I was confused from the Modbus slave side and not the READ_VAR instruction. the problem was with the Modbus slave documentation and couldn't understand the what are the Modbus register addresses(4XXXX or 3XXXX) available from the slave. now it's being figured out and got the comms working. Thank you all for the replies and support.
-Arun

 

[tragically1969]

So you asked :

I am bit confused how I am gonna used the READ_VAR instruction to read this register from T200 unit

But Meant:

Actually, I was confused from the Modbus slave side and not the READ_VAR

Erm , OK.......

 

[arun_mallah]

Thanks for it

I am so sorry, I didn't notice that until you pointed out. next time i will take care.
-Arun