Specifications
AirPrime UMTS / LTE MC/SL-Series Extended AT Command Reference
86 Proprietary and Confidential 2130616
Command reference
Table 4-2: Diagnostic command details
Command Description
!CMUX
Supporting chipsets:
• MDM6200
• MDM6270
• MSM6290
• QSC6270
Implement multiplexing mode
This command implements the functionality of +CMUX (27.007 standard command). It is
provided to ensure command consistency with Sierra Wireless CDMA modules.
See 3GPP TS 27.007 for command syntax and arguments.
!CMUXLPBK
Supporting chipsets:
• MDM6200
• MSM6290
Configure ports into loopback mode/query loopback state
Use this command to select a multiplexed port and to loop data traffic between the host
and the modem over that port.
The modem is effectively in loopback mode only after the modem is put into MUX mode
(using +CMUX). You can, however, issue !CMUXLPBK before or after +CMUX.
Loopback mode is NOT supported on the MUX control channel, since flow control and
other modem signaling is passed on this port.
Usage:
• Execution: AT!CMUXLPBK=<bitmask>
Response:
OK
Purpose: Select a specified multiplexed port.
• Query: AT!CMUXLPBK?
Response:
!CMUXLPBK: <bitmask>
OK
Purpose: Return the current setting.
You can have two ports in loopback mode.
When the modem is in loopback mode, the loopback occurs just as data is passed to the
application layer of the modem. Therefore, the processing time of this command
includes the processing overhead of packet disassembly and reassembly as the packets
are received and echoed back to the host.
To exit loopback mode when the AT data port is in loopback, you must reset the modem.
To exit loopback mode on other ports, enter the command with the appropriate bit in the
bitmask set to 0. To disable loopback mode on all ports, enter AT!CMUXLPBK=0x00.
Parameters:
<bitmask> (16-bit hexadecimal bitmask that identifies the port)
• Bit 0: AT data port
• Bit 1: Diag port
• Bit 2: HIP (CnS) port
• Bit 3: Reserved
• Bit 4: PDP1 port
• Bit 5: Reserved
• Bit 6: Reserved
• Bit 7–15: Reserved
Examples:
AT!CMUXLPBK=0x01—Sets the AT data port into loopback mode
AT!CMUXLPBK=0x10—Sets PDP1 into loopback mode