TX321 Transmitter for GOES or Meteosat


The TX321 is a GOES and Meteosat satellite data transmitter. It provides an easy and reliable way for Campbell Scientific data collection platforms (DCP) to transmit data over geostationary satellites. The TX321 is typically used by government agencies and sponsored research organizations for the purpose of collecting environmental data.

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Benefits and Features

  • GOES High Data Rate Version 2, Meteosat SRD, and International DCS operation
  • Very low power consumption when idle (< 5 mA @ 12V)
  • Transmissions continue for 28 days if GPS is lost
  • Configuration and diagnostics easily performed by datalogger or computer
  • Drop-in replacement for Campbell Scientific TX320, TX312, and SAT HDR GOES


TX321-G GOES Transmitter, front and top view
TX321-G GOES Transmitter, front and top view
TX321-G GOES Transmitter, front and top view
TX321-G GOES Transmitter, left and top view
TX321-G GOES Transmitter, right and top view
TX321-G GOES Transmitter, top view
TX321 Transmitter, front view
TX321 Transmitter, left view
TX321-M Meteosat Transmitter, left and top view
TX321-M Meteosat Transmitter, front and top view
TX321-M Meteosat Transmitter, right and top view
TX321-M Meteosat Transmitter, top view
TX321-G GOES Transmitter attached to a CR300 Datalogger (sold separately)
TX321-G GOES Transmitter cabled to a CR300 Datalogger (sold separately)

Detailed Description

The TX321 is designed for use on the NOAA GOES Data Collection System and the EUMETSAT Meteosat Data Collection Services satellite networks. These networks use geostationary satellites and ground stations to receive and relay data transmitted from remote data collection platforms (DCP), such as those provided by Campbell Scientific. These DCPs are typically owned and operated by government agencies and sponsored research organizations. Users are given a frequency and time slot for their transmissions.

Data Collection Platform (DCP) Equipment

  • TX321 Satellite Transmitter
  • 17992 or 31182 GPS antenna and their antenna mounts and coaxial cables
  • 25316 11 dBi Right-Hand Circular Polarized (RHCP) Yagi antenna and coaxial cable
  • Datalogger
  • Power supply, such as Campbell Scientific’s BP12 or BP24 battery, CH150 or CH200 charge regulator, and SP10 10 W or SP20 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. 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
    Email: Letecia.Reeves@noaa.gov

  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.

Meteosat System Authorization Procedure

Complete and submit the EUMETSAT DCP Admission form.


Transmissions Supported
  • Timed and random
  • ASCII and pseudo-binary message
Transmit RF Out Connector Type N jack
Radio Module G6 OEM
Operating Temperature Range -40° to +60°C
Storage Temperature Range -55° to +70°C
Case Dimensions 18.54 x 12.7 x 3.81 cm (7.3 x 5 x 1.5 in.)
Maximum Dimensions 20.96 x 13.34 x 4.06 cm (8.25 x 5.25 x 1.6 in.) including connectors
Weight 0.77 kg (1.7 lb)

Supply Power

Supply Voltage 10.8 to 16 Vdc
Typical Current Drain
  • < 5 mA (at 12 Vdc when idle)
  • < 100 mA (at 12 Vdc during GPS fix)
  • < 2.6 A (at 12 Vdc during transmit)
Connector Removable 2 pin screw terminal, 5 mm pitch

Satellite GOES

Standards NOAA/NESDIS GOES High Data Rate Certification Standards version 2
Baud Rates 300 and 1200 bps
Transmit Power
  • When transmitting to GOES-13 or later, transmit EIRP shall be 37 to 41 dBm for 300 bps and 43 to 47 dBm for 1200 bps.
  • Settings default for use with 11 dBi YAGI antenna
  • 31.5 dBm (300 bps default)
  • 37.5 dBm (1200 bps default)
  • 38 dBm (maximum)
Frequency Range 401.701 to 402.0985 MHz
Initial Frequency Stability ±20 Hz disciplined to GPS (GPS fix occurs after power up and once per day thereafter.)
Channel Bandwidth
  • 3 kHz (300 bps)
  • 1.5 KHzNOAA/NESDIS GOES High Data Rate Certification Standards version 2 (1200 bps)

Satellite Meteosat

Operation EUMETSAT Meteosat SRD
Baud Rates 100 bps
Transmit Power
  • Meteosat SRD transmit EIRP should be 43.25 to 52 dBm.
  • Default configuration for use with 11 dBi YAGI antenna
  • 37.5 dBm (100 bps default)
  • 41.5 dBm (maximum)
Frequency Range 402.0355 to 402.4345 MHz
Initial Frequency Stability ±20 Hz disciplined to GPS (GPS fix occurs after power up and once per day thereafter.)
Channel Bandwidth 3 kHz (100 bps)

GPS Receiver

Receiver Type 3.3 V active
Connector SMA jack


Initial Accuracy ±100 μs (synchronized to GPS)
Drift ±10 ms/day (without GPS)
GPS Schedule 1 fix at power up (1 fix per day afterwards)
Transmission Continuation without GPS Fix 28 days

Interface Connectors

USB Micro B, USB device
RS-232 DB9 F, DCE, 3 wire RS-232
Satellite RF Transmit Out Type N jack
GPS SMA jack
Power Removable 2 pin

Interface Command Protocols

Binary Command Protocol
  • Available on CS I/O when connected
  • Available on RS-232 if CS I/O is not connected
ASCII Command Protocol Available on all ports

25316 Transmit Antenna

Gain 11 dBi
Antenna Type Right-hand circular polarization Yagi
Connector Type N female
Wind Load ~100 knots

17992 GPS Antenna

Antenna Type 3.3 V active dome, pipe mount
Gain 28 dBi
Connector TNC jack

31182 GPS Antenna

Antenna Type 3.3 V active patch, magnetic mount
Gain 27 dBi
Connector SMA plug


Datalogger Considerations

Compatible Contemporary Dataloggers

CR200(X) Series CR800/CR850 CR1000 CR3000 CR6 CR9000X CR300 Series

Compatible Retired Dataloggers

CR500 CR510 CR10 CR10X 21X CR23X CR9000 CR5000 CR7X

*Only the CR295 and CR295X of the CR200(X)-series dataloggers are compatible with the TX321.
♣The CR300 Series requires a null modem cable, pn 18663.

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 can be used if the system contains higher power consumptive devices such as continuous bubblers or heated rain gages.

Note: Because of the peak power draw during transmit, do not connect to the 12V output of a datalogger.

Enclosure Considerations

Compatible Enclosures

ENC10/12 ENC10/12R ENC12/14 ENC14/16 ENC16/18 ENC24/30(S)
* * *

*When installing the TX321 into the ENC10/12R, ENC12/14, or ENC14/16, it must be mounted flat or a right-angle serial connector must be used, such as that offered by the SC12 or a ribbon cable.


TX321 GPS Update v.1 (1 MB) 10-18-2017

This download is a zip file that contains the new firmware for the G6 radio internal to the TX321. The new firmware resolves two issues in the GPS System. The new firmware resolves the UTC offset glitch that caused the transmission to be offset up to 3 seconds. The update also resolves the week number roll over issue and adds support for the next GPS week number roll over on 4/07/2019.  The Zip file also contains the software package that uploads the new firmware and the TX321 firmware update procedure.

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.

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