Product Info

LTE Standard Module Series
EG91 Series Hardware Design
EG91_Series_Hardware_Design
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3.5.1.2. USB Application with USB Remote Wakeup Function
If the host supports USB suspend/resume and remote wakeup functions, the following three preconditions
must be met 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.
Module
USB_VBUS
USB_DP
USB_DM
AP_READY
GND
Host
VDD
USB_DP
USB_DM
GPIO
GND
Figure 4: Sleep Mode Application with USB Remote Wakeup
• Sending data to EG91 series module through USB will wake up the module.
• When EG91 series module has a URC to report, the module will send remote wakeup 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/resume, but does not support remote wakeup 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 suspended state.
The following figure shows the connection between the module and the host.