This product is no longer available and has been replaced by: TX321.
TX320 High Data Rate (HDR) GOES Transmitter
Services Available
Repair No
Calibration No
Free Support Yes


Campbell Scientific’s TX320 is a high data rate (HDR) transmitter that provides communications, via GOES satellites, from a Data Collection Platform (DCP) to a receiving station. It is compatible with most Campbell Scientific data loggers and offers a convenient telemetry option for remote DCPs in the Western Hemisphere.

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Benefits and Features

  • Transmission rates of 300 and 1200 bps
  • Transmitter certified as High Data Rate version 2 compliant
  • NESDIS-certified transmitter
  • Automatic GPS correction of clock and oscillator drift
  • Very stable clock that provides up to 28 days of operation between GPS fixes for more reliable operation in areas with poor GPS reception
  • Diagnostics and status information can be sampled by the data logger and transmitted as part of the data stream
  • Readily added or retrofitted to existing Campbell Scientific systems
  • Non-volatile setups configured with Windows-based software
  • USB port for connecting PCs to setup and perform diagnostics
  • Independent self-timed and random data buffers


Detailed Description

The TX320 supports data transmission rates of 300 and 1200 bps. Because clock accuracy is critically important for GOES satellite telemetry, the TX320 includes a robust, temperature-compensated-oscillator (TCXO) based clock and a GPS receiver. The real-time clock's precision allows independent operation for up to 28 days without GPS correction.

GOES System

GOES satellites have orbits that coincide with the Earth’s rotation, allowing each satellite to remain above a specific region. GOES satellites cover the western hemisphere.

The GOES system is administered by the National Environmental Satellite Data Information Service (NESDIS). NESDIS assigns addresses, uplink channels, and self-timed/random transmit time windows. Self-timed windows allow data transmission only during a predetermined time frame. Random windows are for applications of a critical nature (e.g., flood reporting) and allow transmission immediately after a threshold has been exceeded.

Data Collection Platform (DCP) Equipment

  • TX320 GOES satellite transmitter (includes an SC12 cable)
  • 17992 GPS antenna and the 18017-L cable. The GPS antenna mounts to the end of a crossarm via the 7623 ¾-in. threaded pipe and a 1049 NU-RAIL fitting or CM220 Mount.
  • Data logger
  • 25316 11-dBi Right-Hand Circular Polarized (RHCP) Yagi antenna with mounting hardware.
  • COAXNTN-L RG8 antenna cable
  • ENC16/18 or larger enclosure
  • Power supply consisting of Campbell Scientific’s BP12 12-Ahr, BP24 24-Ahr, or BP84 84-Ahr battery pack, CH200 or CH150 regulator, and SP10 10-W or SP20 20-W solar panel
  • 31320 Surge Protection Kit (optional)

Retrieving Data from the Ground Receiving Station

Choose one of the following methods:

  • Internet (see NESDIS for requirements)
  • Domsat
  • LRGS
  • DRGS (Direct Readout Ground Station)


Operating Voltage Range 10.8 to 16 Vdc
Transmission Data Rates 300 and 1200 bps
Frequency Range 401.7 MHz to 402.1 MHz
Operating Temperature Range -40° to +60°C
Storage Temperature Range -55° to +70°C
Dimensions 24.9 x 5.3 x 15.8 cm (9.8 x 2.1 x 6.2 in.)
Weight 1.02 kg (2.25 lb)

Supply Current @ 12 Vdc

Idle or Sleep 5 mA
During GPS Fix < 70 mA (for 15 minutes per day)
Transmission 2.6 A

Channel Bandwidth

300 bps Transmission Rate 750 Hz
1200 bps Transmission Rate 2250 Hz

USB Port

Connector USB type B
Command Protocols ASCII Command Protocol

CS I/O Port

Signal Levels TTL
Interface Protocol Campbell Scientific Synchronous Device Communication (SDC)
Command Protocol ASCII Command Protocol or Binary Command Protocol ASCII command protocol is described in “G5 ASCII Command Protocol (Document number 700-G5-CMND-ASCII)."

Binary packet protocol is described in “G5 Binary Command Protocol (Document number 700-G5-CMND-BIN)."

RS-232 Port

Signal Levels RS232C
Connector DB9F
Command Protocol ASCII Command Protocol or Binary Command Protocol ASCII command protocol is described in “G5 ASCII Command Protocol (Document number 700-G5-CMND-ASCII)."

Binary packet protocol is described in “G5 Binary Command Protocol (Document number 700-G5-CMND-BIN)."

Output Power

Standards Complies with NOAA/NESDIS, GOES DCPRS Certification Standards at 300 bps and 1200 bps, version 2.0.
For a 1200 bps Link DCPRS shall operate with an EIRP of 43 to 47 dBmi, assuming appropriate antenna.
For a 300 bps Link When transmitting to the GOES-13 or later satellites, the DCPRS shall operate with an effective EIRP of 37 to 41 dBmi, assuming appropriate antenna.
Example Output Power 11.2 W @ 1200 bps transmission rate


Setting Accuracy ±100 µs synchronized to GPS
Drift ±10 ms/day (over -40° to +60°C)
GPS Schedule 1 fix at power up, 1 fix per day afterwards
Transmission Continuation without GPS Fix 28 days

Frequency Stability

Initial Accuracy ±20 Hz disciplined to GPS
Short-Term Drift ±0.04 Hz/seconds
Aging ±0.1 PPM/year
Vcc + Temperature ±0.1 PPM


Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.

Data Loggers

Product Compatible Note
21X (retired)
CR10 (retired) The CR10 requires a special PROM.
CR1000 (retired)
CR10X (retired) For a mixed-array CR10X, use OS version 1, revision 15 through 19. For CR10X-PB, use the most current operating system; the RAWS-7 format is not supported by the CR10X-PB.
CR200 (retired)
CR200X (retired)
CR205 (retired)
CR206 (retired)
CR206X (retired)
CR210 (retired)
CR211 (retired)
CR211X (retired)
CR215 (retired)
CR216 (retired)
CR216X (retired)
CR23X (retired)
CR295 (retired)
CR295X (retired)
CR3000 (retired)
CR500 (retired)
CR5000 (retired)
CR510 (retired)
CR800 (retired)
CR850 (retired)
CR9000 (retired)
CR9000X (retired)

Additional Compatibility Information

Environmental Enclosure

The TX320 transmitter needs to be housed in an ENC16/18, ENC24/30, or ENC24/30S environmental enclosure. You can order the enclosure with the 19332 and 19336 Antenna Cable/Bulkhead accessories that will allow the Yagi and GPS antennas to be connected without opening the enclosure door.

Power Supply

Typical power supply is a BP12 12 Ahr or BP24 24 Ahr battery, CH150 or CH200 regulator, and an SP10 or SP20 solar panel. The BP85 or a user-supplied deep-cycle rechargeable battery should be used when it is difficult to replace the batteries or the system's power requirements are large. The deep-cycle rechargeable battery should have at least a 60 Ahr capacity, and be trickle-charged with an 20 W solar panel.

GOES System Authorization Procedure

Non-U. S. government agencies and research organizations must have a sponsor from a U.S. government agency. Prospective GOES users must receive formal permission from NESDIS, by doing the following:

  1. Fill out the System Use Agreement (SUA) application form, which is available at

    The form can be submitted online or sent to:

    GOES DCS SUA Processing Unit NOAA,
    Satellite Services Division
    4231 Suitland Road, Rm 1646
    Suitland Federal Center Suitland, MD 20746
    Tel: 301-817-4563
    Fax: 301-817-4569

  2. Following approval, NESDIS sends a Memorandum of Agreement (MOA). The MOA must be signed and returned to NESDIS.
  3. After the MOA is approved, NESDIS will issue a channel assignment and an ID address code.
  4. NESDIS must be contacted to coordinate a start-up date.


TX320 & TX321 USB Drivers v.2.08.28 (1.64 MB) 03-05-2013

TX320 & TX321 USB Drivers for the Windows operating system. 32 and 64 bit support for Windows 8, Windows 7, Windows Vista and Windows XP.

Note: Drivers should be loaded before plugging the TX320 or TX321 into the computer.

TX321 / TX320 GPS Update v.4 (1.09 MB) 12-18-2019

This download is a zip file that contains new firmware v11.11 and v10.23 for the G6 radio internal to the TX321 and v8.04 for the G5 radio internal to the TX320.
The file also contains the software package that uploads the new firmware and the TX321 / TX320 firmware update procedure.

View Update History

Frequently Asked Questions

Number of FAQs related to TX320: 1

Case Studies

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As concern over changing climate conditions in the world was growing in the late 1990s, more

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