Precision Digital PD865 - Manual (Page 48)

PD865 Snooper Modbus Serial Input Meter Instruction Manual
48
Relay Operation After Communications Break
When a Master meter fails to receive a reply from the slave it is called a
Communications Break. The relays can be programmed to react to this
event by going On, Off, or No Action. After communications is restored
the relays are turned off or on based on their operating mode and their
set and reset points, without regard to their prior state. This is similar to
the auto initialization on power up. Below is a diagram showing three
examples.
The same is true for a meter set up to operate in Snooper mode.
Relay 1
Manual mode
Relay 2
Manual mode
Input
de-energized
energized
Relay 3
Auto mode
Relay 1 Set
Relay 1 to 3
Reset
Relay 2 Set
Relay 3 Set
Communications
Break
Communications
Restored
No Serial
Communications
Communications
Break: No Action
Communications
Break: Relay "on"
Communications
Break: Relay "on"