Omni8/16C/Omni8P User Manual
UMC1480R24.pdf
61
© Omniflex 2021
5.5
Selecting the Group Alarm Relay (RL3) Output Function
The Group Alarm (G.A.) relay RL3 offers a changeover contact on Terminal Strip D.
SW1-6 and SW1-7 are used to set the mode of operation of this relay.
There are four modes to choose from:
1.
Relay follows input
The relay is normally energised.
Any abnormal input will de-energise the relay. The relay will re-energise when all inputs return to their
normal states, regardless of the state of the alarm lamps.
This is useful for tracking the actual state of the inputs. Any abnormal input will cause the relay to be de-
energised.
2.
Relay follows alarm state
The relay is normally energised.
Any alarm state will de-energise the relay. The relay will return to normal when all alarm states have
returned to normal. (i.e. the alarms have been acknowledged by the operator and the entire display is off)
This is useful for tracking the actions of a local operator in clearing the problem. If a ‘fleeting’ alarm
sequence is chosen, the relay will remain de-energised until the operator clears the display, even though
the input contact may have already returned to the normal state.
3.
Relay acts as ring-back horn
The relay is normally de-energised.
The G.A. relay will energise when any abnormal input returns to normal. The RESET pushbutton must be
depressed to return the G.A. to its normal state.
(This G.A. type can be used to alert an operator to the fact that an alarm has returned to its normal state).
4.
Relay acts in Multiple Reflash Mode
The relay is energised with all inputs in their normal state.
The relay is de-energised by the first input changing to the abnormal state.
Upon each subsequent input changing to the abnormal state, the relay will momentarily energise (for
about 1 second), then return to the de-energised state.
This is useful when the relay contact is used for example to trigger a dial up alarm, and if subsequent
inputs going into alarm must also trigger the dial-up alarm.
Referring to Table 5-3, select one of the 4 relay modes by setting switches SW1-6 and SW1-7 to the
appropriate positions.
