M1 Support Forum Random System Start Up – Input Card Reply To: Random System Start Up – Input Card

Bryan Cargould

    The system consists of one home run bus through a M1DBH with 4 keypads, 2 expansion input cards, 1 expansion output card, one UPB interface, and the terminator. None of the keypads or expansion card are using terminating resistors and the measured Bus resistance was 51.1 Ohms with the terminating resistor and 70.5 without.

    The total bus run lengths counting both ways on each run is between 450 and 550 feet total of Cat 6 cable.

    There is a secondary power supply powering the Ethernet interface and the audio card. It is also wired to an input for monitoring only and the negative is connected to the main negative terminal where the battery negative is also connected.

    System Diagnostics reports a Voltage of 13.8 and Current of 0.42 amps, measured voltage is around 13.5.

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