LTE Standard Module Series
EC25 Hardware Design
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Figure 4: Sleep Mode Application with USB Remote Wakeup
Sending data to EC25 via USB will wake up the module.
When EC25 has a URC to report, the module will send remote wake-up signals via USB bus so as to
wake up the host.
3.5.1.3. USB Application with USB Suspend/Resume and RI Function
If the host supports USB suspend and resume, but does not support remote wake-up function, the RI
signal is needed to wake up the host.
There are three preconditions to let the module enter sleep mode.
Execute
AT+QSCLK=1
command to enable sleep mode.
Ensure the DTR is held at high level or keep it open.
The host’s USB bus, which is connected with the module’s USB interface, enters suspend state.
The following figure shows the connection between the module and the host.
Figure 5: Sleep Mode Application with RI