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6.4 Input Time Delay – Option AD*
As an option each channel can be provided with a potentiometer, which allows the user to select a
time delay to prevent the alarm from occurring unless it has been present for a pre-defined period.
Option AD1 = Adjustable Delay Range 5 – 50 ms
Option AD2 = Adjustable Delay Range 20ms - 2 seconds
Option AD3 = Adjustable Delay Range 5ms – 5 seconds
6.5 Input Wiring Segregation
Field contacts are often great distances from the annunciator it is therefore advisable to run the
contact cables separately from circuits carrying heavy currents and/or high voltages to minimise the
affects of induced voltages.
6.6 No Master Module
Each dual channel alarm card is equipped with a dedicated application specific integrated circuit
(ASIC). System control is automatically allocated to one of the alarm cards during power on and if
this card is removed, damaged or fails (apart from catastrophic failure), another card will
automatically take over the common control functions. This method of operation eliminates the need
for a traditional style common services/control module and removes common failure points thus
increasing reliability.
