I have a couple of questions concerning the initialization of the real time clock.
In the owner’s Manual the command (T) is described in two ways; Shared Mode and Backup mode.
Will Shared mode correctly continue the RTC when the power is shut down? (I believe the answer is no)
Can I assume Backup mode needs both an external crystal and a battery power supply? The SDR board does not seem to have an external clock location but does have an external VBAT pin. Does this mean the SDR card can not utilize the backup mode?
The manual also says it is important to use the (T) command before setting the time (section 7.4.4). Does this mean that it has to be done once for initial setup and that setting will then hold no matter how many times the power is turned off/on, or once each time the power is toggled on/off or each time you set the time?