WEG CFW-11 Communications Manual page 55

Possible Causes/Correction:
Verify the times programmed in both master and slave, for the message exchanging. In order to avoid
problems due to transmission delays and differences in the time counting, it is recommended that the values
programmed for message exchanging in the master be a little bit shorter than the times programmed for the
error detection by the slave.
guarding
Verify if the master is sending the telegrams in the programmed time.
Verify communication problems that can cause telegram losses or transmission delays.