User Guide

HE910 Hardware User Guide
1vv0300925 Rev.18 – 15-06-2012
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 24 of 91
A flow chart showing the proper turn on procedure is displayed below:
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 HE910 when the module is powered off or during
an ON/OFF transition.
Modem ON Proc.
Y
Y
HW unconditional
SHUTDOWN
AT init sequence.
Start AT CMD.
N
PWMON = ON?
PWMON = ON?
AT answer in 1Sec ?
N
Y
N
Delay 1s
DELAY= 300mSec
ON_OFF = LOW
Delay = 5 Sec
ON_OFF = HIGH
Enter AT<CR>