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Retired Product

This product is no longer available and has been replaced by: TX320. Some accessories, replacement parts, or services may still be available.

Technical Description

The TX312 uses the GOES satellite system to provide one-way communications from a data collection platform (DCP) to a receiving station. This satellite transmitter complies with the High Data Rate (HDR) specifications. Supported transmission rates are 100, 300, and 1200 bps. Because clock accuracy is critically important for GOES satellite telemetry, the TX312 includes a robust, TCXO-based real-time clock and a GPS receiver. The TX312 is compatible with most of our dataloggers (see Compatibility tab).

GOES System

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.

TX312 and SAT HDR GOES Comparison

The TX312 replaced the SAT HDR GOES in 2005. The TX312 provides the following advantages over its predecessor, the SAT HDR GOES:
  • Up to 28 days of operation between GPS fixes
  • Every unit tested by Campbell Scientific in an environmental chamber to ensure the unit operates within specifications
  • Additional LEDs that indicate transmitter’s operation
  • Easier to use Windows-based software for configuring the non-volatile setups

TX312 Specifications

  • Operating Voltage Range: 10.8 to 16 Vdc
  • Supply Current (@ 12 Vdc): 5 mA at idle, 2.6 A during transmission
  • Transmission Data Rates: 100, 300, and 1200 bps
  • Channel Bandwidth: 1.5 kHz @ 100 bps transmission rate; 1.5 kHz @ 300 kHz @ 300 bps transmission rate; 3.0 kHz @ 1200 bps transmission rate
  • Output Power: Complies with NESDIS DCPRS Certification Standards, Section 4. For 1200 bps, it has a nominal EIRP of 51 dBm and a maximum EIRP of 53 dBm, assuming appropriate antenna. For 100/300 bps, it has a nominal EIRP of 48 dBm and a maximum EIRP of 50 dBm, assuming appropriate antenna
  • Timekeeping
    • Setting Accuracy: ±100 µs synchronised to GPS
    • Drift : ±10 msec/day over -40º to 60ºC
    • GPS Schedule: 1 fix at power up, 1 fix per day afterwards
    • Transmission Continuation w/o GPS Fix: 28 days
  • Frequency Range: 401.7 MHz to 402.1 MHz
  • Frequency Stability
    • Initial Accuracy: ±20 Hz disciplined to GPS
    • GPS Schedule: 1 fix at power up, 1 fix per day afterward
    • Short-Term Drift: ±0.04 Hz/seconds
    • Aging: ±0.1 PPM/year
    • Vcc + Temperature: ±0.1 PPM

Refer to the product brochure for additional specifications.