Omron DRM21 module prompts E2 error, how to do?

Cause: indicates that the network communication timeout. Countermeasures: 

① Check the main station must use the same baud rate from the station;
 
② Check the wiring of communication cable is loose;
 
③ whether the two terminals of the network terminating resistor;
 
④ check the current speed and distance network, consider reducing the baud rate of the network, using 125Kbps baud rate for communication;
 
⑤ recommended DeviceNet dedicated cable network;

⑥ Whether there is signal interference around the communication apparatus.