Detcon Four Channel Relay Card - Manual (Page 9)

4 Channel Relay Card
Four Channel Relay Card Instruction Manual Rev. 1.2 Page 5 of 8
3.2.1 Silencable or Non Silenceable
Alarms 1, 2, and 3 can be configured as Silencable or Non-Silenceable. In order for an alarm to be
Silenceable, the corresponding DIP switch must be set to Silenceable, and an external ‘Normally Open,
Momentary Closed Switch’ must be connected to the ‘Reset’ connector on the Relay Card. If an alarm relay is
configured as Silenceable and it is in an alarm state, it can be returned to its normal state (silenced) by
activating the external reset switch. If a relay is configured as Non-Silenceable and is in an alarm state, the
activation of the external reset switch has no effect. The ‘Fault’ alarm cannot be silenced.
NOTE:
If a relay has been silenced and the sensor input drops below the alarm level the alarm will
reset. If the sensor input again rises above the alarm level the relay will again enter an
alarm state. If another sensor (one that did not cause the original alarm) goes into alarm,
then the relay will be reactivated.
3.2.2 Latching or non-Latching Relays
Alarms 1, 2, and 3 can be configured as Latching or Non-Latching. If a relay is configured as Non-Latching,
the relay returns to its normal state once the alarm has cleared or passed. If the alarm is set as Latching the
relay remains in the alarm state even after the alarm has cleared. An alarm that is set as ‘Latching’ can only be
returned to its normal state by activation of an external reset switch.
3.2.3 Energized or Non-Energized
Alarms 1, 2, and 3 can be configured as Energized or Non-Energized. The standard is Non-Energized.
However, a relay can be configured as energized to provide application specific features. A normally
energized relay will de-energize when in alarm. A typical application of the energized configuration is to have
the alarm relay normally energized so that in the event of a power failure to the control module card, the alarm
relay will de-energize causing its relay contacts to change state, thereby creating an alarm output.
3.2.4 Fault
The only configuration option for the fault relay is latching or non-latching. If the Fault alarm is configured as
‘Latching’ the fault relay will energize whenever a fault occurs, and will remain latched (energized) until the
fault has cleared, and the ‘Reset Switch’ has been pushed. The ‘Fault’ alarm cannot be silenced.
 The fault circuitry monitors the sensors attached to the controller. If a sensors mA input falls below
2.2mA the fault circuitry will generate a ‘Fault’.
 If a sensor is attached to the Relay Card, with no alarm levels or more than three alarm levels
configured, the card will generate a ‘Fault’
3.3 Reset
The reset connector provides connections for an external ‘Normally Open, Momentary Closed Switch’. This
switch is used to reset and/or silence alarms if the alarms are set as latching, and/or Silenceable.