Campbell TX325 User manual

Revision: 10/2020
Copyright © 2019 – 2020
Campbell Scientific, Inc.

Table of contents
1. Introduction 1
2. Precautions 1
3. Initial inspection 1
4. QuickStart 2
4.1 Data collection platform (DCP) installation 4
5. Overview 7
5.1 GOES, NESDIS, and transmit windows 8
6. Specifications 10
7. Installation 11
7.1 Field site requirements 11
7.2 LED function 12
7.3 Ports and connectors 13
7.4 Transmission antenna 14
7.5 GPS antenna 14
7.6 Data logger programming 14
7.6.1 Read and write settings 16
7.6.2 Read-only settings 17
8. Troubleshooting 19
8.1 Troubleshooting over-air transmissions 20
Appendix A. Eligibility and getting onto the GOES system 23
Appendix B. Data formats and transmission durations 24
B.1 ASCII data format 24
B.1.1 7-byte floating-point ASCII (GOESTable() format option 1) 24
B.1.2 ASCII table space (GOESTable() format option 2) 26
B.1.3 ASCII table space, comma separated (GOESTable() format option 3) 29
B.1.4 Line SHEF (Standard Hydrological Exchange Format) (GOESTable() format
option 6) 31
B.2 Pseudobinary data formats 32
Table of Contents - i

B.2.1 Campbell Scientific FP2 data 33
B.2.2 Pseudobinary 38
B.2.3 Additional pseudobinary representations 38
B.3 Transmission durations 38
Appendix C. Compliance documents and certificates 40
Table of Contents - ii

1. Introduction
The TX325 transmitter sends data via Geostationary Operational Environmental Satellites (GOES),
and is the successor to the TX321. In the Western Hemisphere, the TX325 is compatible for use
with NOAA GOES DCS with a coverage range including Canada, the United States of America,
and Mexico—as well as most countries in Central America and many South American countries.
The TX325 is the telemetry backbone for many data collection platforms (DCP) that use GOES.
The satellite transmitter can be integrated with a number of Campbell Scientific data loggers and
is an available communications option for many systems, serving a wide range of applications.
2. Precautions
lREAD AND UNDERSTAND the Safety section at the back of this manual.
lAlthough the TX325 is rugged, it should be handled as a precision scientific instrument.
lA proper antenna connection is required before transmission occurs. Failure to use a
properly matched antenna cable and antenna may cause permanent damage to the radio
frequency (RF) amplifiers.
lThe TX325 requires an active GPS antenna with a maximum gain of 25 dB. The TX325 will
supply 3.3 V to the active GPS antenna.
3. Initial inspection
lUpon receipt of the TX325, inspect the packaging and contents for damage. File damage
claims with the shipping company.
lCheck the ships with list to ensure all components are received.
TX325 Satellite Transmitter for GOES V2 1

4. QuickStart
Use our Device Configuration Utility to enter the required National Environmental Satellite Data
and Information Service (NESDIS) information that is unique to each data collection platform
(DCP). This QuickStart is for the CR6 (≥OS 10), CR300-series (≥OS 10), CR1000X (≥OS 4), and
GRANITE-series (≥OS1) data loggers.
1. Connect the data logger RS-232 to the TX325 RS-232 connector and connect the data
logger to a power supply. Also ensure the TX325 has power.
2. Connect to the data logger using Device Configuration Utility.
a. Do the following to directly connect your data logger to the Device Configuration
Utility:
i. Use the USB cable to connect the data logger to the computer.
ii. Click your data logger model for the Device Type in the Device Configuration
Utility.
iii. Click Direct for the Connection Type.
iv. Select the COM port on the computer to which the data logger is connected.
v. Click Connect.
b. For data loggers on an IP connection, do the following to remotely connect with the
Device Configuration Utility:
i. Click your data logger model for the Device Type in the Device Configuration
Utility.
ii. Click IP for the Connection Type.
iii. Type the Server Address.
iv. Type the PakBus/TCP Password.
v. Click Connect.
3. Click the Settings Editor tab.
TX325 Satellite Transmitter for GOES V2 2

4. Click the GOES Radio sub tab (FIGURE 4-1 (p. 3)).
FIGURE 4-1. Device Configuration Utility GOES Radio screen
5. Select Enabled from the Goes Radio Enabled field.
6. Select the Com Port to which the GOES radio is connected.
7. Type the Self-timed Message Windows (in seconds) as assigned by the GOES DCS Program.
8. Type the Platform ID (in HEX) as assigned by the GOES DCS Program.
9. Select the Random Transmission Baud Rate as assigned by the GOES DCS Program.
10. Type the Random Transmission Channel as assigned by the GOES DCS Program.
11. Select the Self-Time Baud Rate as assigned by the GOES DCS Program.
TX325 Satellite Transmitter for GOES V2 3

12. Type the Self-Time Channel as assigned by the GOES DCS Program.
13. Type the Random Transmission Interval as assigned by the GOES DCS Program. Format is
hh:mm:ss.
14. Type the Self-timed Transmission Interval as assigned by the GOES DCS Program. Format is
dd:mm:hh:ss.
15. Type the Self-timed Transmission Offset as assigned by the GOES DCS Program. Format is
hh:mm:ss.
16. Click the Deployment tab.
17. Click the Com Port Settings sub tab.
18. Select 9600 for the Baud Rate.
19. Click Apply to save the changes.
Now the settings are stored in the data logger. CRBasic programming is required to push data
over the network. The GOESTable() and GOESField() CRBasic instructions used in
conjunction with DataTable() facilitate the transmission of data across the GOES satellite
network.
4.1 Data collection platform (DCP)
installation
1. Yagi antenna installation procedure:
a. Mount the Yagi antenna to a pole or mast by using the U-bolts included with the
antenna mount.
TX325 Satellite Transmitter for GOES V2 4

b. Attach elements to boom.
NOTE:
When attaching elements to the boom, make sure to place them such that the
number of grooves on the element equals the number of dimples on the boom.
For example, the element with four grooves should be placed at the spot on the
boom with four dimples, and so forth.
c. Aim the Yagi antenna at the spacecraft; azimuth and elevation angle positions are
included on the bracket label.
2. GPS antenna installation procedure:
a. Connect the GPS cable to the GPS antenna.
b. Route the cable through the 0.75-inch IPS threaded pipe and insert the pipe into the
GPS antenna.
TX325 Satellite Transmitter for GOES V2 5

c. Mount the 0.75-inch IPS threaded pipe to a crossarm by using the Nu-Rail® fitting,
or CM220 mounting bracket.
CAUTION:
The GPS antenna will not receive a GPS signal through steel roofs or steel walls.
Concrete might also be a problem. Heavy foliage, snow, and ice will attenuate
the GPS signal.
3. Mount the TX325, the power supply, and the data logger to the backplate of an enclosure.
4. Mount the enclosure and solar panel to the pole or tripod.
TX325 Satellite Transmitter for GOES V2 6

5. Connect the COAXNTN cable to the Yagi antenna. Route the COAXNTN cable through the
enclosure conduit and connect it to the RF Out connector on the TX325 (FIGURE 4-2 (p.
7)).
FIGURE 4-2. TX325 connectors
6. Route the GPS antenna cable through the enclosure conduit and connect it to the GPS
connector on the TX325 (FIGURE 4-2 (p. 7)).
7. Plug the green connector from the power supply to the green receptacle on the TX325.
8. Connect the data logger to the TX325 RS-232 terminal.
9. Route the solar panel cable through the enclosure conduit and connect the red and black
wires to the CHG terminals on the CH150 or CH200.
5. Overview
The TX325 can transmit either self-timed or random GOES messages to the GOES West and GOES
East satellites. In a typical configuration, the TX325 is connected to a data logger via an RS-232
serial connection. The data logger makes measurements, then formats those values to create a
data packet, which is transferred to the transmitter at time of transmission. The data logger
buffers the message until its transmission window (or random transmission time), then transmits
the data at either 300 or 1200 bps.
TX325 Satellite Transmitter for GOES V2 7