When #SIMDET=1 (that simulates "SIM Inserted") is issued, a
query to detect the presence of the SIM is forced, regardless of
SIMIN pin status.
If SIM is not responding (for example, because it is not present)
then, after a timeout, the modem gives up and sets the SIM status
to SIM NOT INSERTED.
If SIM is correctly answering to query, then SIM status becomes
SIM READY.