Question:  I have a Median frame in one room and a PSU-101 / IMF-3 frame with interfaces located in a adjacent equipment room.  I would like the Median frame to trigger its external alarm if the PSU-101 experiences an issue with its power supplies, can this be done with a wired connection from the PSU-101 alarm contacts to the Median frame external alarm contacts?
Answer:  The Median frame can support external alarm contacts from a PSU-101 power supply see the wiring diagram below for the pin outs from the Median frame external alarm DB-9 connector and the PSU-101 4-pin Jones type connector on the rear of the power supply:











Pins are provided for adding an additional alarm source to the matrix’s alarm system. Pin 6 is an alarm input to the Eclipse Median matrix. It is connected to the input of a 3.3 V logic device. A logic high on this input will cause the Eclipse Median to detect an alarm condition. A logic low or an open circuit will cause the Eclipse Median to detect no alarm condition.
Pin 1 is a voltage source out of the Eclipse Median matrix. It is connected through a 10K Ohm pull-up resistor to the +5 V supply rail inside the Eclipse Median matrix.  A contact closure placed across pins 1 and 6 will also cause an alarm condition. The alarm outputs of the PSU-101 power supply could be wired directly to these pins allowing the CPU card to report PSU failures also.