DOC-0017-07-EN: AC20 Series - EtherCAT Option  
46 (58)  DOC-0017-07-EN-B  04.04.2023  
10  Lost Communication Trip 
Supervised Parameter: 
The 0777 Comms Supervised parameter indicates that the EtherCAT network participation is supervised 
by another EtherCAT device. 
The Supervised parameter value is set to TRUE when either:  
The heartbeat consumer and Heartbeat producer is enabled and error free. 
Node guarding is enabled and error free. 
Note that the watchdog will not be available if the Read Process data size is zero, in which case the 
Supervised parameter will be FALSE. 
 
Comms Break Trip 
The drive will trip when there is a loss of communications between the master and the drive. 
A COMMS BREAK trip will occur if the 0777 Comms Supervised parameter transitions from TRUE to 
FALSE and the drive is in the operational state. 
The trip may be disabled by clearing the respective bit in the parameter 0870 Enable Trips Lo. The 
parameter Enable Trip Lo is a 32-bit word, the bit number 27 is used to disable or to enable the trip. 
 
Comms state 
The parameter 0774 Comms State indicates ‘PROCESS_ACTIVE’ when the EtherCAT communication is 
active. The table below describes how the comms state relates to the EtherCAT network: 
 
INIT, BOOTSTRAP or PRE-Operational 
Operational: the network process data channel is active 
(Error Ind’-bit in ‘AL-Status’ is set) 
EtherCAT interface is forced to INIT state, and the master is informed that a power 
cycle is required to resume communication