-does it check to see if SIM 1 is working every 30 mins (enable automatic switching) or every minute (Switch back to primary SIM card after timeout)
A time interval in sec after which the router checks for condition changes corresponding to SIM switch rules. If such condition exist, the router will perform a SIM switch, if not - it will check for the same conditions again after the amount of time specified in this field.
-every minute (Switch back to primary SIM card after timeout)
Switch back to primary SIM card after timeout is a SIM switching rule that can only be configured on the secondary SIM card. It's purpose is to switch the router back to using the primary SIM after a SIM switch rule is triggered for the primary SIM card.
A subsequent timeout value added to Initial timeout if the previous attempt to switch back to primary SIM failed. This value is increased every time an unsuccessful switch-back is made:
new_timeout = old_timeout + subsequent_timeout
Example: Let's say you've configured a rule that dictates the router to switch to Secondary SIM if signal strength falls below -90 dBm and a rule that will switch back to Primary SIM with both the initial and subsequent timeouts of 1 minute (i.e., Initial timeout = Subsequent timeout = 1). If signal strength does indeed fall below this threshold, the router will switch to Secondary SIM card, wait 1 minute (Initial timeout), switch back to Primary SIM card, check the signal strength value and, if signal strength value is still below -90 dBm, switch back again to Secondary SIM card. This time the router will try to switch back to Primary SIM card after 2 minutes, i.e., new_timeout = old_timeout + subsequent_timeout = 1 minute + 1 minute = 2 minutes. The third time the router will 3 minutes, the fourth time - 4 minutes, and so on until the signal strength of the Primary SIM card rises above -90 dBm.