Campbell Scientific ST-20 User Manual
ST-20 Argos Satellite
Transmitter
Picture of ST-20
Revision: 6/07
Copyright © 2006-2007
Campbell Scientific, Inc.
Warranty and Assistance
The ST-20 ARGOS SATELLITE TRANSMITTER is warranted by
CAMPBELL SCIENTIFIC, INC. to be free from defects in materials and
workmanship under normal use and service for twelve (12) months from date
of shipment unless specified otherwise. Batteries have no warranty.
CAMPBELL SCIENTIFIC, INC.'s obligation under this warranty is limited to
repairing or replacing (at CAMPBELL SCIENTIFIC, INC.'s option) defective
products. The customer shall assume all costs of removing, reinstalling, and
shipping defective products to CAMPBELL SCIENTIFIC, INC. CAMPBELL
SCIENTIFIC, INC. will return such products by surface carrier prepaid. This
warranty shall not apply to any CAMPBELL SCIENTIFIC, INC. products
which have been subjected to modification, misuse, neglect, accidents of
nature, or shipping damage. This warranty is in lieu of all other warranties,
expressed or implied, including warranties of merchantability or fitness for a
particular purpose. CAMPBELL SCIENTIFIC, INC. is not liable for special,
indirect, incidental, or consequential damages.
Products may not be returned without prior authorization. The following
contact information is for US and International customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company
serves your country. To obtain a Returned Materials Authorization (RMA),
contact CAMPBELL SCIENTIFIC, INC., phone (435) 753-2342. After an
applications engineer determines the nature of the problem, an RMA number
will be issued. Please write this number clearly on the outside of the shipping
container. CAMPBELL SCIENTIFIC's shipping address is:
CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784
CAMPBELL SCIENTIFIC, INC. does not accept collect calls.
ST-20 Table of Contents
PDF viewers note: These page numbers refer to the printed version of this document. Use
the Adobe Acrobat® bookmarks tab for links to specific sections.
1. Overview.......................................................................1
1.1 Specifications............................................................................................1
1.2 Serial Port.................................................................................................1
1.3 Data Buffers..............................................................................................3
1.4 Multiple Argos ID Numbers.....................................................................3
1.5 One Argos ID Number .............................................................................3
2. Datalogger Programming............................................3
2.1 Argos Setup ..............................................................................................3
2.1.1 Result Code.....................................................................................4
2.1.2 Buffer Number................................................................................4
2.1.4 Frequency........................................................................................4
2.2 ArgosData.................................................................................................4
2.2.1 General Description........................................................................4
2.2.2 ResultCode......................................................................................4
2.2.3 ST20Buffer .....................................................................................4
2.2.4 DataTable........................................................................................4
2.2.5 NumRecords ...................................................................................5
2.2.6 DataFormat .....................................................................................5
2.3 ArgosDataRepeat......................................................................................5
2.3.1 Result Code.....................................................................................5
2.3.2 Repetition Rate................................................................................5
2.3.3 Number Repeats..............................................................................5
2.3.4 Buffer Number................................................................................5
2.4 ArgosTransmit..........................................................................................6
2.4.1 Result Code.....................................................................................6
2.4.2 Buffer Number................................................................................6
2.5 ArgosError (Error as string) .....................................................................6
2.5.1 ErrorCodes......................................................................................6
3. ST-20 Installation.........................................................6
3.1 BNC Antenna Connector and Antenna.....................................................6
3.2 Environmental Enclosure..........................................................................7
4. Satellite Orbit Patterns................................................7
5. Antenna Placement .....................................................7
i
ST-20 Table of Contents
Figures
Table
1-1. ST-20 Argos Satellite Transmitter.......................................................... 1
1-2. ST-20 with CR1000 Datalogger in Enclosure........................................ 2
1-1. ST-20 Serial Port Configuration............................................................. 2
ii
ST-20 Argos Satellite Transmitter
1. Overview
The ST-20 is a certified Argos PTT satellite transmitter for use with Campbell
Scientific, Inc. CRBasic dataloggers. Service Argos data transceivers fly
aboard two NOAA polar orbiting satellites. With an orbit altitude close to 800
kilometers, the satellites are at a relatively low orbit. The low orbit allows for
low transmit power, low battery power requirements and the use of an omnidirectional antenna. The orbit period is approximately 1 hour and 45 minutes,
which allows hourly data at extreme northern and southern latitudes. Near the
equator there are about six satellite passes per day that are not evenly spaced.
During the average satellite pass, the satellite is in view for about 10 minutes.
1.1 Specifications
Power supply: Nominal 12 volts DC, 10 volts DC minimum,
Current drain at
12 volts:
Data Buffers: 7 buffers, 32 byte each. Note: 28 bit ID numbers reduce
Dimensions: 7.5 L x 2.25 H x 1.25 W inches, 19 L x 6 H x 3 W cm.
Weight: 7.9 oz, 224 gm
1.2 Serial Port
The ST-20 is specifically designed to work with Campbell Scientific, Inc.
CRBasic dataloggers. The ST-20 serial port is connected to the CS I/O port of
the datalogger. The datalogger provides 12 volt DC po wer and gr o un d thr ou g h
pins 8 and 2 respectively. Communications utilize the Campbell Scientific,
Inc. Synchronous Device for Communications (SDC) protocol, which allows
several devices to be connected to the CS I/O port at the same time. Each
device is addressed or pin enabled; the ST-20 is address 4.
FIGURE 1-1. ST-20 Argos Satellite Transmitter
16 volts DC maximum
1.12 mA quiescent, 375 mA during transmit
buffers to 31 bytes.
1
Loading...