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2-wire interface has x32 dry contact inputs (digital inputs) (IN). It can be used together with any contacts, for example, doors, windows, fire alarms, burglar alarms, power systems, circuit breakers, exit/push buttons and etc.
VT900 and VT900DC monitoring systems support only one dry contact board extension. Either VTx40a or VTx16.
VT960 and VT960DC support up to x3 dry contact extensions.
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