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PQMT Commands

Below, are excerpts for a few of the PQTM messages from the GNSS Protocol Specification manual. Users will find these useful for configuring their LG290P GNSS module as an RTK base station or rover.

Documentation

A full list of PQTM messages (proprietary NMEA messages defined by Quectel) supported by LG290P, is provided in section 2.3. PQTM Messages of the GNSS Protocol Specification manual. This protocol is used to configure or read the settings for the LG290P GNSS module.

List of Proprietary Quectel Messages

Message Type Mode Message Description
PQTMVER Output Outputs the firmware version
PQTMCOLD Input Performs a cold start
PQTMWARM Input Performs a warm start
PQTMHOT Input Performs a hot start
PQTMSRR Input Performs a system reset and reboots the receiver
PQTMUNIQID Output Queries the module unique ID
PQTMSAVEPAR Input Saves the configurations into NVM
PQTMRESTOREPAR Input Restores the parameters configured by all commands to their default values
PQTMVERNO Output Queries the firmware version
PQTMCFGUART Input/Output Sets/gets the UART interface
PQTMCFGPPS Input/Output Sets/gets the PPS feature
PQTMCFGPROT Input/Output Sets/gets the input and output protocol for a specified port
PQTMCFGNMEADP Input/Output Sets/gets the decimal places of standard NMEA messages
PQTMEPE Output Outputs the estimated position error
PQTMCFGMSGRATE Input/Output Sets/gets the message output rate on the current interface
PQTMVEL Output Outputs the velocity information
PQTMCFGGEOFENCE Input/Output Sets/gets geofence feature
PQTMGEOFENCESTATUS Output Outputs the geofence status
PQTMGNSSSTART Input Starts GNSS engine
PQTMGNSSSTOP Input Stops GNSS engine
PQTMTXT Output Outputs short text messages
PQTMCFGSVIN Input/Output Sets/gets the Survey-in feature
PQTMSVINSTATUS Output Outputs the Survey-in status
PQTMPVT Output Outputs the PVT (GNSS only) result
PQTMCFGRCVRMODE Input/Output Sets/gets the receiver working mode
PQTMDEBUGON Input Enables debug log output
PQTMDEBUGOFF Input Disables debug log output
PQTMCFGFIXRATE Input/Output Sets/gets the fix interval
PQTMCFGRTK Input/Output Sets/gets the RTK mode
PQTMCFGCNST Input/Output Sets/gets the constellation configuration
PQTMDOP Output Outputs dilution of precision
PQTMPL Output Outputs protection level information
PQTMCFGODO Input/Output Sets/gets the odometer feature
PQTMRESETODO Input Resets the accumulated distance recorded by the odometer
PQTMODO Output Outputs the odometer information
PQTMCFGSIGNAL Input/Output Sets/gets GNSS signal mask
PQTMCFGSAT Input/Output Sets/gets GNSS satellite mask
PQTMCFGRSID Input/Output Sets/gets the reference station ID
PQTMCFGRTCM Input/Output Sets/gets RTCM

Save Parameters/Restore to Default Settings

PQTMSAVEPAR

Saves the current configurations into NVM of the LG290P

$PQTMSAVEPAR*<Checksum><CR><LF>
Example

Save the current settings to non-volatile memory of the LG290P. 

$PQTMSAVEPAR*5A

If there are no errors, users will receive the following response: 

$PQTMSAVEPAR,OK*72

PQTMRESTOREPAR

Restores the parameters configured by all commands to their default values; this command takes effect after restarting the LG290P

$PQTMRESTOREPAR*<Checksum><CR><LF>
Example

Restore all the settings of the LG290P to their factory defaults 

$PQTMRESTOREPAR*13

If there are no errors, users will receive the following response: 

$PQTMRESTOREPAR,OK*3B

UART Settings

PQTMCFGUART

Configures the serial protocol setting for the UART interfaces

  • Current UART interface:

    $PQTMCFGUART,W,<BaudRate>[,<DataBit>,<Parity>,<StopBit>,<FlowCtrl>]*<Checksum><CR><LF>

  • A specific UART interface:

    $PQTMCFGUART,W,<Index>,<BaudRate>[,<DataBit>,<Parity>,<StopBit>,<FlowCtrl>]*<Checksum><CR><LF>

Parameters:

Field <Index> <BaudRate> <DataBit> <Parity> <StopBit> <FlowCtrl>
Description UART Interface
  • 1 = UART1
  • 2 = UART2
  • 3 = UART3
 Baud Rate (bps)
  • 9600
  • 115200
  • 230400
  • 460800
  • 921600
 Number of Data Bits
  • 8 = 8 bits
 Parity
  • 0 = No parity
  • 1 = Odd parity
  • 2 = Even parity
  • 3 = Mark
  • 4 = Space
 Number of Stop Bit(s)
  • 1 = 1 stop bit
  • 2 = 2 stop bits
 Flow Control
  • 0 = None

Baud Rate

For ports utilized in conjunction with either the BlueSMiRF or radio transceivers, we recommend reducing the baud rate to 115200bps or lower to avoid overflowing the buffers of the transceiver's serial port.

Configure the Settings

Example Settings

  • Port: UART1
  • Baud Rate: 115200bps
  • Data Bits: 8
  • Parity: No
  • Stop Bits: 1
  • Flow Control: None

Configure the baud rate of the current UART interface to 115200bps: 

$PQTMCFGUART,W,115200*18

Configure the baud rate of UART1 to 115200bps: 

$PQTMCFGUART,W,1,115200*05

Configure all parameters of the current UART interface: 

$PQTMCFGUART,W,115200,8,0,1,0*11

Configure all parameters of UART1: 

$PQTMCFGUART,W,1,115200,8,0,1,0*0C

If there are no errors, users will receive the following response: 

$PQTMCFGUART,OK*60

Retrieve the Settings

Example Settings

  • Port: UART1
  • Baud Rate: 115200bps
  • Data Bits: 8
  • Parity: No
  • Stop Bits: 1
  • Flow Control: None

Get the configuration on the current UART interface: 

$PQTMCFGUART,R*36

Get the configuration on UART1: 

$PQTMCFGUART,R,1*2B

If there are no errors, users will receive the following response: 

$PQTMCFGUART,OK,1,115200,8,0,1,0*5F

PQTMCFGPROT

Configures the input/output protocol on a specified port

$PQTMCFGPROT,W,<PortType>,<PortID>,<InputProt>,<OutputProt>*<Checksum><CR><LF>

Parameters:

Field <PortType> <PortID> <InputProt> <OutputProt>
Description Port Type
  • 1 = UART
 Port ID
  • 1 = UART1
  • 2 = UART2
  • 3 = UART3
 Input/Output Protocols (HEX: 32-bit)
  • Bit 0 = NMEA
  • Bit 2 = RTCM3
The default protocols are NMEA and RTCM3:
HEX: 00000005
BIN: 0000 0000 0000 0000 0000 0000 0000 0101

Configure the Settings

Example Settings

  • Port: UART1
  • Input Protocol: NMEA & RTCM3
  • Input Protocol: NMEA & RTCM3

Configure the configuration on UART1: 

$PQTMCFGPROT,W,1,1,00000005,00000005*38

If there are no errors, users will receive the following response: 

$PQTMCFGPROT,OK*6B

Retrieve the Settings

Example Settings

  • Port: UART1
  • Input Protocol: NMEA & RTCM3
  • Input Protocol: NMEA & RTCM3

Get the configuration on UART1: 

$PQTMCFGPROT,R,1,1*3D

If there are no errors, users will receive the following response: 

$PQTMCFGPROT,OK,1,1,00000005,00000005*6B

RTK Settings

PQTMCFGSVIN

Configures a base station's position either by survey-in mode or fixed mode

$PQTMCFGSVIN,W,<Mode>,<CFG_CNT>,<3D_AccLimit>,<ECEF_X>,<ECEF_Y>,<ECEF_Z>*<Checksum><CR><LF>

Parameters:

Field <Mode> <CFG_CNT> <3D_AccLimit> <ECEF_X> <ECEF_Y> <ECEF_Z>
Description Receiver Mode
  • 0 = Disable
  • 1 = Survey-in mode
  • 2 = Fixed mode
    (Position is configured in ECEF coordinates)
 Survey-in Mode
Minimum positioning time (seconds)
  • Range: 0-86400
  • Default: 0
 Survey-in Mode
3D positioning accuracy (meters)
  • 0 = No limit
  • Default: 0.0
 Fixed Mode
WGS84 ECEF X,Y,Z coordinates (meters)
  • Default: 0.0000

RTK Base Station Modes

In order to operate as a base station, the LG290P GNSS module requires an accurate position of its antenna. This can be either defined in ECEF coordinates or acquired through a self-survey process.

  1. Survey-In Mode: The base station's location is established based on a weighted mean of recent solutions of its position. The <CFG_CNT> and <3D_AccLimit> parameters define the shortest amount of time that the position gets surveyed and the maximum standard deviation of the estimated position.
  2. Fixed Mode: The base station's position is provided in ECEF coordinates.

Note

Any error in the base station's location will translate directly into an error in the rover's position.

Configure the Settings

Example Settings

  • Mode: Survey-in mode
  • Survey Time: 3600 seconds
  • 3D Accuracy: 1.2m
  • ECEF Coordinates:
    • X: -2519265.0514m
    • Y: 4849534.9045m
    • Z: 3277834.6432m

Configure the configuration on UART1: 

$PQTMCFGSVIN,W,1,3600,1.2,-2519265.0514,4849534.9045,3277834.6432*01

If there are no errors, users will receive the following response: 

$PQTMCFGSVIN,OK*70

Retrieve the Settings

Example Settings

  • Mode: Survey-in mode
  • Survey Time: 3600 seconds
  • 3D Accuracy: 1.2m
  • ECEF Coordinates:
    • X: -2519265.0514m
    • Y: 4849534.9045m
    • Z: 3277834.6432m

Get the configuration on UART1: 

$PQTMCFGSVIN,R*26

If there are no errors, users will receive the following response: 

$PQTMCFGSVIN,OK,1,3600,1.2,-2519265.0514,4849534.9045,3277834.6432*52

PQTMCFGRCVRMODE

Configures the mode that the receiver is operating in

$PQTMCFGRCVRMODE,W,<Mode>*<Checksum><CR><LF>

Parameters:

Field <Mode>
Description Operation mode
  • 0 = Unknown
  • 1 = Rover
    When set to this mode, the receiver will restore to default NMEA message output state.
  • 2 = Base Station
    When set to this mode, the receiver will automatically disable NMEA message output and enable RTCM MSM4 and RTCMv3 1005 message output.

Note

After switching the module‘s working mode, save the configuration and then reset the module. Otherwise, it will continue to operate in the original mode.

Configure the Settings

Example Settings

  • Port ID: UART1
  • Input Protocol: NMEA & RTCM3
  • Input Protocol: NMEA & RTCM3

Configure the configuration on UART1: 

$PQTMCFGRCVRMODE,W,2*29

If there are no errors, users will receive the following response: 

$PQTMCFGRCVRMODE,OK*64

Retrieve the Settings

Example Settings

  • Port ID: UART1
  • Input Protocol: NMEA & RTCM3
  • Input Protocol: NMEA & RTCM3

Get the configuration on UART1: 

$PQTMCFGRCVRMODE,R*32

If there are no errors, users will receive the following response: 

$PQTMCFGRCVRMODE,OK,2*7A

PQTMCFGRTK

Configures the operation settings of the RTK mode

$PQTMCFGRTK,W,<DiffMode>,<RelMode>*<Checksum><CR><LF>

Parameters:

Field <DiffMode> <RelMode>
Description Differential Mode
  • 0 = Disable RTK/RTD feature (Differential data is not used)
  • 1 = Auto mode
  • 2 = RTD only mode (Only pseudoranges is used)
 Absolute/Relative Mode
  • 1 = Absolute mode, ensure absolute position accuracy
  • 2 = Relative mode, ensure relative position accuracy
This field only takes effect when <DiffMode> = 1 and the module enters the RTK only mode.

Configure the Settings

Example Settings

  • Port ID: UART1
  • Input Protocol: NMEA & RTCM3
  • Input Protocol: NMEA & RTCM3

Configure the configuration on UART1: 

$PQTMCFGRTK,W,1,1*6C

If there are no errors, users will receive the following response: 

$PQTMCFGRTK,OK*3F

Retrieve the Settings

Example Settings

  • Port ID: UART1
  • Input Protocol: NMEA & RTCM3
  • Input Protocol: NMEA & RTCM3

Get the configuration on UART1: 

$PQTMCFGRTK,R*69

If there are no errors, users will receive the following response: 

$PQTMCFGRTK,OK,1,1*3F