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

Brad Weeks

    How many total bus devices are connected to the M1 and how are they wired 1) M1DBH, 2) M1DBHR or 3) Daisy Chained? Are there more than two home runs connected to the M1? If using the M1DBH is the overall Data Bus wiring less than 2000 feet or if Daisy Chaining less than 4000 feet? Do you have any secondary power supplies powering bus devices and if so there is a Common DC Negative between the M1 and the secondary power supply? In the case of a secondary power supply the +12V of the M1 should not be connected to the device if using a secondary power supply. With the entire system powered down including any secondary power supplies measure the resistance across Data A and Data B at the M1 Main Board — you should measure ~60-70Ω Ohms. If you measure 120Ω we’re missing a terminating jumper and if less than 40Ω too many terminating jumpers. With the system powered UP measure the voltage at each device. You should measure 12-14 VDC. If less than 12 this could cause issues.


    The M1 System has been designed in that if it detects any operational anomalies, regardless how small or big or the cause it will attempt to “Self-heal Itself” in the most expedient manner. It does this in order to restore itself to a functionally operational state. This event is logged as a System Startup – Control or Bus Device. Has anything changed either with the M1 System or the environment at this location?


    You are currently running M1 Firmware 5.3.14 and  M1G Firmware 5.3.18 is available which has code changes to address and improve System Start-ups which might be occurring. You may want to consider updating the M1 Firmware to see if this makes a difference.

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