Benefits and Features
Well-suited for remote meteorological and environmental data-collection applications, including mobile and highlatitude installations
Provides uplink capability for up to eight unique ID codes, frequencies, and repetition periods
Supports up to seven independent Argos data buffers that can be populated in real-time
Transmits variable-length Argos messages with either 20- or 28-bit ID codes
Allows researchers to forgo a rigorous certification process
Includes an autorepeat feature that allows the ST-21 to repeat data without host intervention
Provides a fail-safe feature that alerts users upon communication linkor host failure
Allows the ID and repetition ratesto be set in real-time or by Campbell Scientific

Technical Description
While Campbell Scientific's ST-21 Argos PTT is based on Telonics' ST-21, they are not equivalent; our ST-21 includes a case, voltage regulator, and our SDC communication interface.
Please note that when ordering the transmitter, the customer needs to provide Campbell Scientific with the number of buffers, repetition rate, decimal ID, Dex ID, frequency, and fail safe information.
To use the Argos system, you must receive formal permission from Service Argos and pay a fee. The data must be used for environmental purposes. Examples include meteorological/hydrological stations, ship tracking, volcano monitoring, and seismic data.