User Guide

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GM500-U1G_A
Hardware Development Guide
VBAT
high level
POWER_ON
Module
Status
Turning offRunning
T2
T3
Power off
Figure 2–7Timing of Turning off Mode
Mode 2:
Send command of AT+ZTURNOFF, and the power off process will take 15s at least.
Note:when using modules, you need to avoid power off abnormally and frequently, as it will cause several risks shown
as below:
1. it will damage the flash permanently.
2. it can’t send deregister message to e-NodeB, and the MMS takes for the module is still registering to network, and it
won’t remind "the user can’t reach" or "the user has turn down" when it’s called(MT).
2.7. Reset Scenarios
When the software stops response, you can pulled down RESET_N pin(pin2) for 1 second to reset the module's system.
When MCU can provide high/low level pulse with 1 second, the reference circuit to reset module is as shown in the following
figure below. The resistors in Figures below are only the recommended value and they need to adjust according to the actual situation.