User's Manual

21
5.7. Turning the Unit OFF By ON/OFF pin
There are two ways to turn off the unit: apply logic low, 0V, to ON/OFF pin or by “turn off” AT command. When IO200 is
powered off by disconnecting the power to the unit, IO200 doesn’t deregister. SIM card might be damaged, and units containing
IO200 that need to pass SIM card type approval tests will fail due to the SIM’s incorrect power off sequence.
There is a risk that if power is removed to soon after applying OFF, the Flash or SIM may be corrupted since the radio would still
be in process of writing to these memories. Therefore, 11 seconds delay from Off event (AT command or de-assertion of 4V
from ON/OFF pin) to B+ removal is required.
Figure 1. On/Off
O
p_
Sel
_
1
Op_Sel_2
DSR
IO200
Modem
Host
Host Wake-U
p
DTR
RX, TX, RTS, CTS, RI, DCD
Pin #25
Pin #26
Pin #11
Pin #10
Pin #6