BECKHOFF ET1100 - Manual (Page 51)

Appendix
Slave Controller – Application Note FAQ 47
10. Press the “Write” button to write the new value, which in fact clears the error counter.
Figure 23: Write to the error counter to clear it
6.2 TwinCAT hints
If communication errors are present, TwinCAT tries to close ports automatically to maintain stable
network operation. If you want to observe the instable network part, you have to re-open the ports
manually (e.g., by resetting the devices, or writing to the appropriate ESC registers). If TwinCAT
closes the ports again, try setting TwinCAT to INIT mode.