Service Guide

Table Of Contents
LTE Standard Module Series
EG915U_Series_Hardware_Design 30 / 90
In this case, three preconditions can make the module enter the sleep mode.
Execute AT+QSCLK=1 to enable sleep mode.
Ensure the MAIN_DTR is held at high level or keep it open.
Ensure the host’s USB bus, which is connected with the module’s USB interface, enters suspend
state.
The following figure illustrates the connection between the module and the host.
USB_VBUS
USB_DP
USB_DM
AP_READY
VDD
USB_DP
USB_DM
GPIO
Module MCU
GND
GND
MAIN_RI
EINT
Figure 5: Sleep Mode Application with MAIN_RI
You can wake up the module by sending data to it through USB.
When the module has a URC to report, the URC will trigger the behaviors of MAIN_RI pin. See
Chapter 4.10.3 for details about MAIN_RI behaviors.
3.2.2.3. USB Application without USB Suspend Function
If the host does not support USB suspend function, disconnect USB_VBUS with an external control circuit
to make the module enter into sleep mode.
Execute AT+QSCLK=1 command to enable sleep mode.
Ensure the MAIN_DTR is held at a high level or keep it open.
Disconnect the USB_VBUS.
The following figure illustrates the connection between the module and the host.
USB suspend is supported on Linux system but not on Windows system.
NOTE