### Magnavox MX4200 GPS Receiver

#### Synopsis

Address: 127.127.9.u
Reference ID: `GPS`
Driver ID: `GPS_MX4200`
Serial Port: `/dev/gpsu`; 4800 baud, 8-bits, no parity
Features: `ppsclock` (required)

#### Description

This driver supports the Magnavox MX4200 Navigation Receiver adapted to precision timing applications. It requires the `ppsclock` line discipline or streams module described in the Line Disciplines and Streams Modules page. It also requires a gadget box and 1-PPS level converter, such as described in the Pulse-per-second (PPS) Signal Interfacing page.

This driver supports all compatible receivers such as the 6-channel MX4200, MX4200D, and the 12-channel MX9212, MX9012R, MX9112.

Leica Geosystems acquired the Magnavox commercial GPS technology business in February of 1994. They now market and support former Magnavox GPS products such as the MX4200 and its successors.

Leica MX9400N Navigator.

#### Operating Modes

This driver supports two modes of operation, static and mobile, controlled by clock flag 2.

In static mode (the default) the driver assumes that the GPS antenna is in a fixed location. The receiver is initially placed in a "Static, 3D Nav" mode, where latitude, longitude, elevation and time are calculated for a fixed station. A DOP-weighted running average position is calculated from this data. After 24 hours, the receiver is placed into a "Known Position" mode, initialized with the calculated position, and then solves only for time.

In mobile mode, the driver assumes the GPS antenna is mounted on a moving platform such as a car, ship, or aircraft. The receiver is placed in "Dynamic, 3D Nav" mode and solves for position, altitude and time while moving. No position averaging is performed.

#### Monitor Data

The driver writes each timecode as received to the `clockstats` file. Documentation for the NMEA-0183 proprietary sentences produced by the MX4200 can be found in MX4200 Receiver Data Format.

#### Fudge Factors

`time1 time`
  Specifies the time offset calibration factor, in seconds and fraction, with default 0.0.
`time2 time`
  Not used by this driver.
`stratum number`
  Specifies the driver stratum, in decimal from 0 to 15, with default 0.
`refid string`
  Specifies the driver reference identifier, an ASCII string from one to four characters, with default `GPS`.
`flag1 0 | 1`
  Not used by this driver.
`flag2 0 | 1`
  Assume GPS receiver is on a mobile platform if set.
`flag3 0 | 1`
  Not used by this driver.
`flag4 0 | 1`
  Not used by this driver.

Additional Information

Reference Clock Drivers