How many total bus devices are connected to the M1 System 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? If you have a secondary power supplies powering bus devices then you will need 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 which time 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. Has anything changed either with the M1 System or the environment at this locations? The reasons which could cause a System Start Up vary including data bus wiring, data bus termination, voltage drops, environmental, transient spikes, rules which might cause some type of endless loop or perhaps a faulty circuit board. In these scenarios we need to check / verify proper data bus configuration and termination, proper voltage levels at each device and that devices which are powered from the M1 are working properly.