5G Module Series
RG255C-GL_Mini_PCIe_Hardware_Design 31 / 57
4.5.3. DTR
The DTR signal is used for sleep mode control. It is pulled up by default. When the module is in sleep
mode, driving DTR low can wake up the module. For more details about the preconditions for the module
to enter sleep mode, see
Chapter 3.2
4.5.4. PERST#
The PERST# signal can be used to force a hardware reset. The module can be reset by driving the
PERST# signal low for 150
–460 ms and then releasing it. The PERST# signal is sensitive to interference.
The traces should be as short as possible and be surrounded with ground.
The reset scenario is illustrated in the following figure.
V
IL
0.5 V
V
IH
2.3 V
VCC_3V3
150 ms
Resetting
Module
Status
Running
PERST#
Restart
460 ms
Figure 13: Reset Timing
4.5.5. LED_WWAN#
LED_WWAN# is an open collector output signal, it is used to indicate the network status of the module,
and its maximum input current can be up to 40 mA. According to the following circuit, to reduce the
current of the LED, a resistor must be placed in series with the LED. The LED emits light when the
LED_WWAN# output signal is active low.
The execution of
AT+CFUN
does not affect GNSS function.
NOTE
