This product is no longer available. Some accessories, replacement parts, or services may still be available.
| Services Available | |
|---|---|
| Repair | No |
| Calibration | No |
| Free Support | No |
Overview
Campbell Scientific’s ST-21 is a Service Argos-certified Platform Transmitter Terminal (PTT ) that transfers data from the datalogger site to the Argos Data Collection and Location System via NOAA polar orbiting satellites. This transmitter is well suited for remote meteorological and environmental data collection applications, including mobile and high-latitude installations. The ST-21 is compatible with our newer dataloggers.
Read MoreBenefits and Features
- Well-suited for remote meteorological and environmental data-collection applications, including mobile and high-latitude 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 link or host failure
- Allows the ID and repetition rates to 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.
Platform Transmitting Terminal (PTT) Equipment
- ST-21 Argos transmitter (includes an SC12 cable)
- CR800, CR850, CR1000, or CR3000 Datalogger
- 12022 antenna (includes antenna cable and mounting bracket)
- Environmental enclosure
- Power supply consisting of our BP12 12-Ahr or BP24 24-Ahr battery pack, CH100 or CH200 regulator, and SP10 10-W or SP20 20-W solar panel
Retrieving Data from the Ground Receiving Station
Choose one of the following methods:
- Phone modem with MNP level 4 error correction (most Hayes-compatible modems contain this error-checking protocol; check the operator’s manual for your modem) and user-supplied communication software (e.g., Procomm Plus, Crosstalk).
- Internet
- Telnet
Images
Specifications
| Operating Temperature Range | -30° to +70°C |
| Supply Voltage | 12 V (nominal) |
| Output Impedance | 50 Ω |
| High Power Level | 800 mW typical (27 to 31 dbm) |
| Argos Transmission Frequency | 401.618 to 401.680 MHz |
| Modulation (BPSK) | -1.1 to +1.1 ±0.1 radians |
| Spurious Emissions | -45 dB |
| Transmission Distance or Area | Worldwide |
| Current Drain |
|
| Service Requirements | Must receive formal permission from Service Argos and pay a fee. Must use data for environmental purposes. |
| Dimensions | 19.05 x 3.18 x 5.72 cm (7.5 x 1.25 x 2.25 in.) |
| Weight | 224 g (7.9 oz) |
Compatibility
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
Dataloggers
| Product | Compatible | Note |
|---|---|---|
| CR1000 (retired) | ||
| CR1000X | ||
| CR200X (retired) | ||
| CR216X (retired) | ||
| CR300 (retired) | ||
| CR3000 | ||
| CR5000 (retired) | ||
| CR6 | ||
| CR800 (retired) | ||
| CR850 (retired) | ||
| CR9000X (retired) |
Additional Compatibility Information
Data Logger Considerations
Our data loggers can format the data as bits per data point, allowing the user to select the resolution used for each data point.
Enclosure Considerations
The ST-21 requires a desiccated, non-condensing environment; a Campbell Scientific enclosure is recommended. Grommets and screws are provided to attach the ST-21's flanges to the backplate of our enclosures.
Subscribing to Argos
To subscribe to Argos, the following steps must be completed:
- Obtain a Program Application Form from the Service Argos website (www.argosinc.com) or from one of the following offices:
North America
CLS America, Inc.
1441 McCormick Drive, Suite 1050
Largo, MD 20774
Tel (301) 925-4411
E-mail: useroffi ce@argosinc.com
Website: www.clsamerica.com
Europe
CLS/Service Argos
8-10, rue Hermes
Parc Technologique du Canal
31520 Ramonville Saint-Agne, France
Tel +33 (0)5 61 39 47 00
E-mail: info@cls.fr
Website: www.cls.fr - Fill out and submit the application form to the appropriate Service Argos office. Service Argos will send you a program review stating whether your program has been approved.
- Following approval, send a Technical File that describes the required data processing and type of results to the appropriate Service Argos office.
- Complete and return a Service Agreement to the appropriate Service Argos office.
Resources and Links
Product Brochures
Miscellaneous
FAQs for
Number of FAQs related to ST-21: 5
Expand AllCollapse All
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The ST-21 is not used via wire. The ST-21 is only used for one-way data transmission via radio frequency to polar-orbiting spacecraft. Limited data throughput with very low power requirements works best at high latitudes.
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Data throughput is dependent on latitude. The spacecraft are polar orbiting, which creates more frequent satellite passes at higher latitudes. Each satellite pass can provide 15 to 90 data points, depending on cost.
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No. The ST-21 is designed for one-way communication only.
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Email delivery or web-based access.
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Fees are set by CLS (Argos). Generally there is a fee for each day the service is used. For details, contact Argos.
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