SIM800L datasheet(23/73 Pages) SIMCOM

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Figure 12: Timing of power on module

When power on procedure is completed, SIM800H&SIM800L will send following URC to indicate that the

module is ready to operate at fixed baud rate.

RDY

This URC does not appear when autobauding function is active.

Note: Customer can use AT command “AT+IPR=x” to set a fixed baud rate and save the configuration to non-volatile flash

memory. After the configuration is saved as fixed baud rate, the Code “RDY” should be received from the serial port every time

when SIM800H&SIM800L is powered on. For details, please refer to the chapter “AT+IPR” in document [1].

4.2.2.

Power down SIM800H&SIM800L

SIM800H&SIM800L will be powered down in the following situations：

Normal power down procedure: power down SIM800H&SIM800L by the PWRKEY pin.

Normal power down procedure: power down SIM800H&SIM800L by AT command “AT+CPOWD=1”.

Abnormal power down: over-voltage or under-voltage automatic power down.

Abnormal power down: over-temperature or under-temperature automatic power down.

4.2.2.1. Power down SIM800H&SIM800L by the PWRKEY Pin

Customer can power down SIM800H&SIM800L by pulling down the PWRKEY pin for at least 1 second and

release. Please refer to the power on circuit. The power down timing is illustrated in the following figure.

Figure 13: Timing of power down SIM800H&SIM800L by PWRKEY

This procedure makes the module log off from the network and allows the software to enter into a secure state to

SIM800H&SIM800L_Hardware Design_V2.02

2015-07-27

SIM800L 数据表(PDF) 23 Page - SIMCom