Helios PD2-6080/PD2-6081 Modbus
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Instruction Manual
47
Relay and Alarm Operation
Diagrams
The following graphs illustrate the operation of the
relays, status LEDs, and ACK button.
High Alarm Operation (Set > Reset)
For Manual reset mode, ACK can be pressed anytime to turn "off" relay. To
detect a new alarm condition, the signal must go below the set point, and then go
above it.
Low Alarm Operation (Set < Reset)
For Manual reset mode, ACK can be pressed anytime to turn "off" relay. For
relay to turn
back “on”, signal must go above set point and then go below it.
High Alarm with Fail-Safe
Operation (Set > Reset)
Note: Relay coil is energized in non-alarm condition. In case of power failure,
relay will go to alarm state.
Low Alarm with Fail-Safe
Operation (Set < Reset)
Note: Relay coil is energized in non-alarm condition. In case of power failure,
relay will go to alarm state.
