BG77 unsolicited message reception

I am using a BG77 connected via UART (HW flow control enabled) to my MCU. The modem is supposed to open an UDP socket towards a remote server, send and receive data.
I would like a confirmation regarding the way URC message work and how the BG77 can asynchronously inform my MCU that a message (NO SMS, NO CALL, ONLY DATA) from the remote server has been received.

According the document Quectel_BG77_Hardware_Design_V1.1.pdf , paragraph 3.15 the Ring Pin can be used for this purpose.

Through the command AT+QCFG="urc/ri/other,“pulse”,120,1 , the Ring Pin shall outputs 120 ms low pulse when a new URC is received.

So, whenever the modem receives data, it will buffer it and it will drive the Ring Pin low for 120 ms.
Since the HW flow control is enable, I would expect that only when my MCU assert the CTS pin, the URC message “+QIURC:“recv”,” will be sent by the modem.

Are my considerations correct ?
Thanks in advance for your kind support.
Best regards


i thinks , we should set RTS as high level , and the moudle CTS will get it , the URC will be barred