User's Manual

GL865 Hardware User Guide
1vv0300910 Rev.1 – 2011-07-22
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page 18 of 79
NOTE:
The power supply on the pins VBATT and VBATT_PA must be applied
at the same time or for the special application in the first
apply the VBATT_PA and in second time apply VBATT, never vice
versa in this case can be damage the unit.
NOTE:
In order to avoid a back powering effect it is recommended to
avoid having any HIGH logic level signal applied to the digital
pins of the GL865 when the module is powered OFF or during an
ON/OFF transition.
A flow chart showing the AT command managing procedure is displayed below:
Modem ON Proc.
Disconnect PWR
supply
AT init
sequence.
Delay 300mS
Enter AT<CR>
AT answer in
1second ?
Y
N
Start AT CMD.