S7-300 PLC comms over ethernet

Hello,

I have a running S7-300 PLC that I am unable to shut down. I also have a new S7-300 PLC that I am able to shut down.

I am using the provided GET function to extract data from the existing PLC to the new PLC. This is working wonderfully.

I've tried adding the PUT function to the new PLC to place data on the existing PLC and this is not working. The status and error information both reads 0, like nothing is working. It is set up the same way that my GET function is set up.

I know that I can use a GET function on the existing PLC. The problem is that I cannot shut it down to update the network configuration, so that it can see the new PLC.

Any suggestions? I am just trying to transfer and read one integer of data from each system.

Thanks for your help!

For the PUT in the new PLC, have you configured an unspecified connection in NetPro and loaded it to the PLC ?

In the old PLC, what used/free connections are listed of the various types when you check the online properties ?

Does there need to be a unique connection for the put function? I've been trying to use the same ID that I have specified in the GET function.

I'm not sure if I understand where to look to answer your second question. I can click the old PLC's CPU and see the existing S7 connection in the table below and that's it. Is that what you were wondering?

Problem solved. I reloaded all my files and configuration and it started working. I have no idea why. Thanks.

The connection has to be loaded into the PLC that is doing the PUT or GET.
Since you have made a PUT in the new PLC, you have to load a connection into the new PLC.
Also, since you cannot (could not ?) stop the old PLC, the connection to be loaded into the new PLC would have to be an unspecified connection type.

Just curious, how and why are you trying to stop the PLC?