Trying connect PLC S7-300 315-2 PN/DP with PM8000 through Modbus TCP/IP

Hello,
yes, you can use the FB for test purposes without license. I recommend to start with the sample project and check the error counter and done counter in CONTROL_DAT as well as save_STATUS when the error counter increases.

"it doesn't work" is no proper description of your situation.

Does the S7 act as client or server?
Do you use TIA or STEP7 classic?
Do you get conn_established=TRUE?

Regards,
Kaulquappe

Hello,
did you check save_STATUS? I expect that you get error A100.

The server waits for connection establishment of the client and does not recognize it. Possible reasons are:
- wrong IP address
- wrong port number
- firewall blocks port 502

Regards,
Kaulquappe

Hello,
A090 is a status message, it is displayed with ERROR=FALSE. The errors are displayed with ERROR=TRUE.

I recommend to take a look at the sample to see how you should evaluate the outputs.

Regards,
Kaulquappe

What do you simulate, the Modbus client or do you use PLCSIM? Please note: PLCSIM can't be used to simulate TCP communication.

When you simulate the client, check the firewall of the PC regarding port 502.

Hello,
is this PM800 a energy meter from Schneider? If yes, this will never be the client, it is a Modbus server. So the S7 must be client.

Irrespective whether the Modbus FB is licensed or not it will establish the connection when it is parameterized properly. Even the outputs are updated every cycle. The only difference is the A090. It is reported in the STATUS when nothing else happens.

Regards,
Kaulquappe