Operating Modes; Power Saving; Sleep Mode; Uart Application - Quectel EC21 Series Hardware Design

3.4. Operating Modes

The table below briefly summarizes the various operating modes referred in the following chapters.
Table 5: Overview of Operating Modes
Mode Details
Idle
Normal
Operation
Talk/Data
Minimum
AT+CFUN command can set the module to a minimum functionality mode without
Functionality
removing the power supply. In this case, both RF function and USIM card will be invalid.
Mode
Airplane
AT+CFUN command or W_DISABLE# pin can set the module to airplane mode. In this
Mode case, RF function will be invalid.
In this mode, the current consumption of the module will be reduced to the minimal level.

Sleep Mode

During this mode, the module can still receive paging message, SMS, voice call and
TCP/UDP data from the network normally.
In this mode, the power management unit shuts down the power supply. Software is not
Power down
active. The serial interface is not accessible. Operating voltage (connected to VBAT_RF
Mode
and VBAT_BB) remains applied.

3.5. Power Saving

3.5.1. Sleep Mode
EC21 is able to reduce its current consumption to a minimum value during the sleep mode. The following
section describes power saving procedure of EC21 module.

3.5.1.1. UART Application

If the host communicates with module via UART interface, the following preconditions can let the module
enter into sleep mode.

Execute AT+QSCLK=1 command to enable sleep mode.

Drive DTR to high level.
EC21_Hardware_Design
Software is active. The module has been registered on the network, and
it is ready to send and receive data.
Network connection is ongoing. In this mode, the power consumption is
decided by network setting and data transfer rate.
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