Campbell Scientific TX320 Transmitter - Manual (Page 22)

TX320 Transmitter
The TX320 supports High Data Rate specifications. The TX320 includes the
following communication ports:
• CS I/O port for Campbell dataloggers
• RS-232 port for dataloggers and PC communication
• USB port for PC communications
The CS I/O port is a Campbell Scientific Synchronous Device for
Communication (SDC) port, address 4.
The 21X and CR7 dataloggers do not support SDC or the
TX320. NOTE
5.1 GOES System
Appendix A provides information about getting onto the GOES system and
eligibility.
5.1.1 Orbit
The TX320 transmitter sends data via Geostationary Operational
Environmental Satellites (GOES). GOES satellites have orbits that coincide
with the Earth's rotation, allowing each satellite to remain above a specific
region. This allows a user to point the GOES antenna at a fixed position in the
sky.
There are two satellites, GOES East and GOES West. GOES East is located at
75° West longitude and GOES West is located 135° West longitude. Both
satellites are located over the equator. Within the United States, odd numbered
channels are assigned to GOES East. Only even numbered channels are
assigned to GOES West. Channels used outside the United States are assigned
to either spacecraft.
5.1.2 NESDIS and Transmit −Windows
GOES is managed by the National Environmental Satellite Data Information
Service (NESDIS). NESDIS assigns the platform ID, uplink channel number,
and self-timed or random transmit windows. Self-timed windows allow data
transmission only during a predetermined time frame (typically 10 seconds
every hour). The self-timed data is erased from the transmitter's buffer after
each transmission, random data is not. Random windows are for critical
applications (for example, flood reporting) and allow transmission immediately
after a threshold has been exceeded. The transmission is then randomly
repeated to ensure it is received. A combination of self-timed and random
transmission can be executed by the TX320.
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