MC60 does not enter sleep mode

IoT Modules GSM Module
1

I have a custom board with a MC60 module. I am monitoring power consumption and DTR pin using a Power Profiler Kit II.

When the program starts, it sets AT+QSCLK=1, activates a PDP context (using CMUX mode) to go online, does some communications and switches DTR from 0 to 1. But this causes no effect. Power consumption does not drop, and in fact if I send more commands to the modem through the main UART (without setting DTR to 0), they are answered normally.

What could be the problem? Does sleep require some special conditions (maybe not using CMUX or any other thing)? The manual lacks a lot of details about how to enter this mode.

2

After some investigation, I have discovered:

  1. When using QSCLK=1 with DTR=1, modem enters sleep mode when in DATA mode, but not when CMUX is enabled.
  2. When using QSCLK=2, modem enters sleep mode also when CMUX is enabled (but I would rather prefer using mode 1.

So, why when using QSCLK=1, DTR is ignored in CMUX mode? Is this a bug?