The M1’s RS485 Data Bus is supervised meaning the M1 polls for bus devices and if a bus devices (Keypad, M1XIN, Wireless Receiver, P212S, M1KAM, M1XSP, etc) fails to respond to a poll the M1 will log this under Menu 8 System Settings, Menu 86 – System Diagnostics, 1 – Data Bus Errors Retry — the T is the Type of Bus Device T1 = Keypads, T2 = Input Expanders including M1XIN and Wireless Receivers (M1XRFTWM, M1XRF319, M1XRF2H), T3 = M1XOVR, T5 = M1XSP , the A is the Address of the Bus Device — for example T2 (Input Expander A3 (Address 3) failed to respond to a poll and the 02841 is the total number of Retries since the last power cycle. It is not uncommon to see the total number of Retries increment as long as it isn’t incrementing very rapidly. In most cases if there was an issue with a bus device then the retries would be incrementing rapidly and there would be a Missing Expansion Module in the M1 LOG.
Factory Defaulting the M1 does not change the firmware in the M1 or any of the bus devices.