Relay Pulsing; Relay Pulsing Sequence; Producing A Relay Pulsing Sequence - Mircom Flex-Net Phase II Application Manual

9.0

Relay Pulsing

Relay pulsing may be required for various setups where a relay will turn ON (close) and then
OFF (open) after a single switch press. An example of relay pulsing is to activate a pre-
recorded digital message using the first pulse and then to deactivate the message with the
second pulse, simulating a maintained switch.
9.1

Relay Pulsing Sequence

The sequence is initiated by either a switch or input circuit changing to an active state. The
changing of state from standby to active satisfies the first condition resulting in an input zone
tagged "Latch A" to become active and maintain its state. Maintaining the state or latching is
performed through advanced logic. See 10.0 Zone Latching.
Once "Latch A" is active, a timer called "Latch A Timer" is started. The timer is used to turn ON
the output relay once it starts running. Once the timer expires, the output relay will turn OFF.
Therefore, the timer is usually set for a short period of time in order to simulate a pulse such as
3 seconds.
The second pulse is generated by the second press or the input circuit changing state to
inactive standby. This will satisfy the second condition and activate "Latch B". "Latch B" will
start a second timer called "Latch B timer" in a similar manner as before. This will pulse the
relay for the second time.
9.2

Producing a Relay Pulsing Sequence

1. Create a monitor input zone. This zone will be activated based on the status of the
switch or input circuit. It will also be referenced in the advanced logic equations for both
latching zones. Tag the zone appropriately such as "Input Switch"
2. Create two (2) timers; Latch A timer and Latch B timer. Specify a time in seconds, for
example 3 seconds. Tag each timer appropriately
3. Create another monitor input zone. This zone will be "Latch A". Highlight the zone and
select the advanced logic tab. Create an equation as shown:
01-00-**-IZ-007 OR (01-00-**-IZ-011 AND NOT **-**-**-TM-021 EQU TIMER_EXPIRED)
Where,
01-00-**-IZ-007 – Input Switch Zone
01-00-**-IZ-011 – Latch A Zone
**-**-**-TM-021 – Latch B Timer
Note – Latch B timer is referenced in the equation in order to un-latch the zone during
the second pulse
4. Create another monitor input zone. This zone will be "Latch A". Highlight the zone and
select the advanced logic tab. Create an equation as shown:
**-**-**-TM-020 EQU TIMER_EXPIRED AND (NOT 01-00-**-IZ-007 OR 01-00-**-IZ-
012)
Where,
**-**-**-TM-020 – Latch A Timer
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Relay Pulsing