User's Manual

Doc No： Topic：
User Manual of TomTom HD
Traffic Receiver Module 1 US
Ver：
1.1
Page：
13 / 39
Page 13 of 39
2.15 Power up / down scenarios
In general, be sure not to turn on the module while it is out of the operating range of voltage in
Chapter 2.2.
2.15.1 Turn on the module
The module can be activated via SYS_EN signal. When switch on the Module the SYS_EN signal
needs to be driven to high level for at least 150ms
2.15.2 Turn off the module
To switching the module off the following procedures may be used:
＊ Normal shutdown:
Software controlled by sending the AT command over the serial application interface.
＊ Automatic shutdown:
Takes effect if under voltage is detected.
2.15.3 Turn off The module using AT command
The best and safest approach to powering down the module is to issue the AT command. This
procedure let the module log off from network and allows the software to enter into a secure
state and safe data before disconnecting the power supply. The mode is referred to as POWER
OFF mode. In this mode, only the RTC stays active.
Command syntax: AT+CPWROFF
Command Possible responses
AT+CPWROFF
Note: switch off the module
OK
Or
CME ERROR: <error>
Test command
AT+CPWROFF=? OK
After sending AT+CPWROFF do not enter any other AT command. There are two ways to verify
when the module turns off.
＊ Wait for the “OK”. It indicates that data have been stored in the non-volatile memory and
the module turn off in less than 1 second.
＊ Also, you can monitor the VIO pin. The low state of VIO definitely that the module is
switched off.