Specifications

SIM7028 Hardware Design V1.00
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PSM will start after the data connection terminated or TAU updated. When the module connects to the
network or update TAU, the network will send timer of T3324 and T3412 to the module, then the module will
enter IDLE mode. In this mode, the module will transfer data with network(DRX status). When the timer of
T3324 over time, the module will enter PSM.
In PSM, the module in power saving status, terminate the connection of network, shut down the most of
power supply, only RTC function is kept, the module cannot be awake. When the timer of T3412 over time,
the module will wake up.
4.3 PSM wake up
In PSM, the network connection of SIM7028 will terminated, the module cannot respond to the request of
user.
If the customer want to use AT command by UART, they need to wake up the module first.
The following methods will wake up the module from PSM:

When the timer T3412 expires, the module will automatically woken up.
 Communicate by LPUART(UART1) with baud rate 9600, send AT command to the module and RXD
has data receiving, the module will automatically woken up
 Pulling WAKEUP pin to low level to wake up the module. When the module detects the falling edge, AT
command must be send in 10ms to wake up the module.

Pulling RESET pin to low level to wake up the module. The module will restart in network registration,
network searching, some settings will lost.