Hi  everyone

I have an S7-1214 server PLC ,, with additional  AI 8 channels analog input card  of which I have to read its  analog inputs directly by the client ,  the client will read the registers starting from  address 30200 to 30204

My question is what is the local addess of process input  image (%IW) i have to set

the address of these analog to be compatible with that modbus address (ie 30200)? 

Hi,

i asume, it is not possible to read/write values directly from/to IW/QW over modbus.

The values have to be stored in a data block at least. So you have to read the values from the analog card inside the cpu-1200 and store the values into a datablock. Afterwards the modbus communication must be set with the data accordingly.

Maybe this FAQ can help.

How do you program and parameterize Modbus/TCP communication between S7-1500 CPUs and S7-1200 CPUs?

regards

sancruz

thank you sancruz for reply

well the manual says it can be read directly 

what you are talking about is holding register data

regards