FAQ: What to do if M241/251 ethernet communication gets interrupted after several hours?

This can come from READ_VAR / WRITE_VAR / READ_WRITE_VAR function blocks called with unreachable server IP address

For example:

• if controller IP address settings are:

Address: 192.168.0.50

Subnet mask: 255.255.255.0

Gateway: 0.0.0.0

• and if READ_VAR tries to communicate with server at address 192.168.10.20

then ethernet port may fail after several hours.

Workaround is :

• Stop trying to reach servers which are not in the same subnet as the controller
• Check ethernet cable status: ETH_R.i_wPortAIpStatus system variable value must be "DATA_EXCHANGE"
• Use a gateway address (use controller address itself if there is no relevant gateway on the network): requests to unreachable server will be redirected to the gateway

Udgivet til: Schneider Electric Danmark