AMG Systems Ltd. reserves the right to make changes to this
document without notice. The information herein is believed to
be accurate. No responsibility is assumed by AMG for its use.
Page 9 of 12
AMG3782RN-DR-SF Instruction Sheet
D16935-01.doc
Alarm Output and Reset Operation
The alarm output and reset is designed to indicate a change of state of the fibre loop or spur attached
to the receiver. The Alarm output is a volts free contact relay output (rating: 0.5A at 125VAC or 1A at
24VDC). It normally open, which means that when not powered the contacts will be open circuit.
On power up the contacts will close and will remain closed for up to 5 seconds. During this time the
receiver will monitor and record the state of the AMG transmit units connected to the receiver.
The contacts will then remain closed until there is a change from this recorded state. A change of state
would be:
Addition or loss of video at any insert node
Addition or loss of primary optical input at any node
Addition or loss of secondary optical input at any node
Power up or down of any node
Loss of power at the receiver
Following a change of state the contacts will remain open, regardless of whether the alarm condition
reverts back to its previous state, until the a reset signal is presented to the alarm input connections.
The alarm reset input is biased at 5V via a 1k
Ω
resistor. To reset the alarm, the alarm reset is required
to be pulled to ground, either by a volt-free contact or an open collector output. The alarm output will
be held in a closed state whilst the alarm reset is connected to ground.
On release of the alarm reset, the alarm output will remain in a closed state until the next change of
state to the AMG transmit unit connected to the receiver. The alarm output may not register a change
of state which happens within 5 seconds of release of the alarm reset.
