GSM/GPRS Module Series
M66 Hardware Design
M66_Hardware_Design Confidential / Released 55 / 80
2) Active during the Call
RFTXMON will be HIGH during a call and the pin will become LOW after being hanged up.
You can execute AT+QCFG=“RFTXburst”, 2 to enable the function.
The timing of the RFTXMON signal is shown below.
RFTXMON
Idle
Calling Hanged up
HIGH
LOW
Figure 39: RFTXMON Signal during Call