PQTM Commands
Quectel proprietary NMEA extensions for the LC29H module family. PQTM commands use named identifiers rather than numeric IDs (contrast with PAIR commands).
All PQTM commands follow standard NMEA framing:
$PQTMCOMMAND,args*CS\r\nRead/Write Convention
Section titled “Read/Write Convention”| Operation | Format |
|---|---|
| Write | $PQTMCFG...,W,args*CS |
| Read | $PQTMCFG...,R*CS or $PQTMCFG...,R,key*CS |
Firmware and System
Section titled “Firmware and System”PQTMVERNO — Query Firmware Version
Section titled “PQTMVERNO — Query Firmware Version”$PQTMVERNO*58Response: $PQTMVERNO,<FW>,<HW>,<ID>,<SDK>,<Date>*CS
PQTMSAVEPAR — Save Parameters to Flash
Section titled “PQTMSAVEPAR — Save Parameters to Flash”$PQTMSAVEPAR*5APQTMRESTOREPAR — Restore Factory Defaults
Section titled “PQTMRESTOREPAR — Restore Factory Defaults”$PQTMRESTOREPAR*13Does not take effect until module is restarted.
PQTMGNSSRESTART — Restart GNSS Engine
Section titled “PQTMGNSSRESTART — Restart GNSS Engine”$PQTMGNSSRESTART,<type>*CS| Type | Name | Behavior |
|---|---|---|
| 1 | Hot start | Retains all cached data |
| 2 | Warm start | Retains almanac; clears ephemeris |
| 3 | Cold start | Clears ephemeris, almanac, position, time |
| 4 | Full cold | Clears all data including configuration |
PQTMGNSSSUSPEND — Suspend GNSS Engine
Section titled “PQTMGNSSSUSPEND — Suspend GNSS Engine”$PQTMGNSSSUSPEND*5BModule remains powered but stops tracking satellites.
PQTMGNSSRESUME — Resume GNSS Engine
Section titled “PQTMGNSSRESUME — Resume GNSS Engine”$PQTMGNSSRESUME*08PQTMFWUPGRADE — Enter Firmware Upgrade Mode
Section titled “PQTMFWUPGRADE — Enter Firmware Upgrade Mode”$PQTMFWUPGRADE*59Port Configuration
Section titled “Port Configuration”PQTMCFGPORT — Configure Serial Port
Section titled “PQTMCFGPORT — Configure Serial Port”Write: $PQTMCFGPORT,W,<port>,<baud>,<input>,<output>*CS
Read: $PQTMCFGPORT,R,<port>*CS
| Parameter | Values |
|---|---|
| port | UART1, UART2, USB |
| baud | 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600 |
| input | NMEA, RTCM3, NMEA|RTCM3 |
| output | NMEA, RTCM3, NMEA|RTCM3 |
Example:
$PQTMCFGPORT,W,UART1,115200,NMEA|RTCM3,NMEA*CSNMEA Message Configuration
Section titled “NMEA Message Configuration”PQTMCFGNMEAMSG — Per-Message Output Rate
Section titled “PQTMCFGNMEAMSG — Per-Message Output Rate”$PQTMCFGNMEAMSG,W,<msgtype>,<uart1_rate>,<uart2_rate>*CSExample: $PQTMCFGNMEAMSG,W,GGA,1,0*CS (GGA on UART1 every fix, disabled on UART2)
PQTMCFGMSGRATE — Generic Message Rate
Section titled “PQTMCFGMSGRATE — Generic Message Rate”$PQTMCFGMSGRATE,W,<msgtype>,<rate>,<port>*CSWorks for any message type including proprietary PQTM output. Example:
$PQTMCFGMSGRATE,W,PQTMSVINSTATUS,1,1*CSNavigation Configuration
Section titled “Navigation Configuration”PQTMCFGEAMASK — Elevation Mask Angle
Section titled “PQTMCFGEAMASK — Elevation Mask Angle”Write: $PQTMCFGEAMASK,W,<degrees>*CS
Range: 0–90 degrees. Default: 5. Excludes low-elevation satellites to reduce multipath.
PQTMCFGCLAMPING — Static Speed Clamping
Section titled “PQTMCFGCLAMPING — Static Speed Clamping”Write: $PQTMCFGCLAMPING,W,<enabled>*CS
Zeros reported speed when receiver is stationary. Useful for vehicle tracking.
Odometer
Section titled “Odometer”PQTMCFGODO — Enable/Disable Odometer
Section titled “PQTMCFGODO — Enable/Disable Odometer”Write: $PQTMCFGODO,W,<enabled>*CS
PQTMRESETODO — Reset Odometer
Section titled “PQTMRESETODO — Reset Odometer”$PQTMRESETODO*CSGeofence
Section titled “Geofence”PQTMCFGGEOFENCE — Configure Geofence Region
Section titled “PQTMCFGGEOFENCE — Configure Geofence Region”$PQTMCFGGEOFENCE,W,<id>,<enabled>,<lat>,<lon>,<radius>*CSUp to 4 independent circular fences (id 0–3). Reports status change on boundary crossing.
Example — 500 m fence:
$PQTMCFGGEOFENCE,W,0,1,37.77490000,-122.41940000,500.0*CSDead Reckoning (BA/CA Variants)
Section titled “Dead Reckoning (BA/CA Variants)”PQTMCFGDRMODE — DR Mode Selection
Section titled “PQTMCFGDRMODE — DR Mode Selection”Write: $PQTMCFGDRMODE,W,<mode>*CS
| Mode | Description |
|---|---|
| 0 | GNSS only — inertial sensors ignored |
| 1 | DR only — GNSS signals ignored |
| 2 | GNSS+DR auto — fuses both sources (recommended) |
PQTMCFGWHEELTICK — Wheel Tick Input
Section titled “PQTMCFGWHEELTICK — Wheel Tick Input”$PQTMCFGWHEELTICK,W,<enabled>,<ticks_per_rev>,<circumference>*CSExample: $PQTMCFGWHEELTICK,W,1,20,2.0000*CS (20 ticks/rev, 2.0 m circumference)
PQTMCFGCAN — CAN Bus Interface (BA Only)
Section titled “PQTMCFGCAN — CAN Bus Interface (BA Only)”$PQTMCFGCAN,W,<enabled>,<baud>*CSTypically 500000 baud for automotive CAN.
PQTMCFGCANFILTER — CAN Message Filter
Section titled “PQTMCFGCANFILTER — CAN Message Filter”$PQTMCFGCANFILTER,W,<id>,<can_id>,<mask>*CSPQTMCFGVEHDBC — Vehicle DBC Configuration
Section titled “PQTMCFGVEHDBC — Vehicle DBC Configuration”$PQTMCFGVEHDBC,W,<dbc_config>*CSVehicle-specific CAN database mapping for speed, wheel tick, and direction signals.
PQTMCFGEINSMSG — Extended INS Status
Section titled “PQTMCFGEINSMSG — Extended INS Status”$PQTMCFGEINSMSG,W,<enabled>*CSOutputs calibration and sensor fusion status for DR diagnostics.
Survey-In (BS Variant)
Section titled “Survey-In (BS Variant)”PQTMCFGSVIN — Configure Survey-In
Section titled “PQTMCFGSVIN — Configure Survey-In”Write:
$PQTMCFGSVIN,W,<mode>,<duration_s>,<accuracy_m>,<ecef_x>,<ecef_y>,<ecef_z>*CSRead: $PQTMCFGSVIN,R*26
| Mode | Description |
|---|---|
| 0 | Disabled |
| 1 | Survey-in — averages fixes for duration_s, locks when accuracy < accuracy_m |
| 2 | Fixed position — uses provided ECEF coordinates directly |
Examples:
$PQTMCFGSVIN,W,1,3600,1,0,0,0*16 (survey-in: 1 hour, 1 m target)$PQTMCFGSVIN,W,2,0,0,-2404572.0411,5381092.5507,2429899.7105*21 (fixed ECEF)PQTMSVINSTATUS — Survey-In Progress
Section titled “PQTMSVINSTATUS — Survey-In Progress”Periodic output — enable via $PQTMCFGMSGRATE,W,PQTMSVINSTATUS,1,1*CS
Reports elapsed time, current 3D accuracy, and convergence status.
Variant Applicability
Section titled “Variant Applicability”| Command Group | AA | BA | CA | DA | BS |
|---|---|---|---|---|---|
| Firmware/System | Y | Y | Y | Y | Y |
| Port Configuration | Y | Y | Y | Y | Y |
| NMEA Message Config | Y | Y | Y | Y | Y |
| Navigation (mask, clamping) | Y | Y | Y | Y | Y |
| Odometer | Y | Y | Y | Y | Y |
| Geofence | Y | Y | Y | Y | Y |
| Dead Reckoning | — | Y | Y | — | — |
| Survey-In | — | — | — | — | Y |
Usage Notes
Section titled “Usage Notes”Parameter persistence. Changes take effect immediately but are lost on power cycle unless saved with PQTMSAVEPAR.
Command ordering. Wait for acknowledgment before sending the next command.
DR calibration. Dead reckoning requires an initial calibration drive. Allow several minutes of driving with good GNSS signal before entering signal-loss areas.