Campbell Scientific SAT User Manual

SAT ARGOS

INSTRUCTION MANUAL

7/01

COPYRIGHT (c) 2000-2001 CAMPBELL SCIENTIFIC, INC.

This is a blank page.

Warranty and Assistance

The

SAT ARGOS 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. To obtain a
Returned Materials Authorization (RMA), contact CAMPBELL SCIENTIFIC,
INC., phone [phone]. 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.

Non-warranty products returned for repair should be accompanied by a
purchase order to cover the repair.

815 W. 1800 N.
Logan, UT 84321-1784
USA
Phone [phone]
FAX [phone]
www.campbellsci.com

Campbell Scientific Canada Corp.
11564 -149th Street
Edmonton, Alberta T5M 1W7
CANADA
Phone [phone]
FAX [phone]

Campbell Scientific Ltd.
Campbell Park
80 Hathern Road
Shepshed, Loughborough
LE12 9GX, U.K.
Phone [phone]
FAX [phone]

This is a blank page.

SAT ARGOS Table of Contents

1. Overview

..................................................................... 1

1.1 Physical.................................................................................................... 2

1.2 Electrical ..................................................................................................2

2. Programming the Datalogger

2.1 Data Packets............................................................................................. 3

2.2 Data Packet Transmission........................................................................ 3

2.3 Datalogger Instruction 125....................................................................... 4

2.3.1 The Active Storage Area................................................................ 4

2.3.2 New Data........................................................................................ 4

2.3.3 P125 Result Codes..........................................................................4

2.3.4 Using Result Codes In the Program ............................................... 5

2.3.5 When to Execute P125................................................................... 5

2.4 Program Example..................................................................................... 5

3. SAT ARGOS Configuration

3.1 SAT ARGOS Power Supply.................................................................... 7

3.2 Pttcomm.exe............................................................................................. 7

3.2.1 Loading the Configuration to the PTT ........................................... 8

4. Satellite Orbit Patterns

....................................... 7

.............................................. 8

.................................... 3

5. Antenna Placement

Figures

1-1 SAT ARGOS ........................................................................................... 1

1-2 SAT ARGOS with Enclosure .................................................................. 3

5-1 Complete Weather Station with PTT....................................................... 9

Table

2-1 P125 Result Codes................................................................................... 5

.................................................... 9

i

This is a blank page.

SAT ARGOS

1. Overview

This Service Argos certified PTT satellite transmitter is well suited for remote
data collection applications. Service Argos data transceivers fly aboard two of
NASA’s polar orbiting satellites. Argos carrier frequency is 401.650 MHz.
With an orbit altitude close to 800 kilometers, the satellites are at a relatively
low orbit. The low orbit allows for a smaller antenna and power supply. The
orbit period is approximately 1 hour and 45 minutes for each satellite. This
orbit period allows hourly data transmission at extreme northern and southern
latitudes. Near the equator there are about six satellite passes per day, but they
are not evenly spaced. Each data transmission can include up to 32 bytes, or
16 Campbell Scientific data points. Data must be decoded by the user, or
Service Argos will decode the data for a fee.

The SAT ARGOS PTT supports up to four Argos ID numbers. Message repeat
intervals, Argos ID numbers and duty cycles can be changed with a simple-to­use computer-based interface. The transmitter connects directly to the CS I/O
port using the standard SC12 ribbon cable. All power and input/output
connections with the datalogger are through the CS I/O port. Power
requirements are approximately 2 mA average current drain. The PTT will
start to transmit two minutes after power is applied. If the datalogger has not
sent data to the transmitter, a default m e ssage is sent. During configuration the
transmitter is disabled. Program instruction P125 is used to send final storage
data to the transmitter. The CR10X datalogger supports the SAT ARGOS.

ANTENNA

Logan, Utah

O

ARGOS TRANSMITTER

ASSEMBLED IN USA

SN:

FIGURE 1-1. SAT ARGOS

DATALOGGER

1

SAT ARGOS

1.1 Physical

1.2 Electrical

The SAT ARGOS PTT is housed in an aluminum enclosure measuring 3” x

2.75” x 1”. There are two electrical connections. The DB9 port connects to
the datalogger CS I/O port. The SMA female port connects to the 50 ohm
impedance antenna.

The SAT ARGOS PTT uses the Campbell Scientific Synchronous Device for
Communication (SDC) protocol. The SDC port (DB9 connector) connects
directly to the datalogger serial port (CS I/O), using the supplied SC12 ribbon
cable. The SDC protocol allows other SDC devices to be connected to the
same serial port. Power is supplied via the SC12 cable, pin 1 and pin 8.

NOTE

Not all CR10X wiring panels supply 12 volts to pin 8. The
CR10X wiring panel must include the text: “CR10X wiring
panel”.

The RF connector is an SMA female; nominal output impedance is 50 ohms.
Transmit power is typically one watt. The anten na is omnidirectional, which is
necessary because the target satellites are not geostationary.

The SAT ARGOS SDC port pin out:

Pin number Function

1 +5 volts
2 Ground
3NC
4 TXD (data out)
5NC
6 SDE (input)
7 CLK/HS (input)
8 +12 volts
9 RXD (data in)

2

SAT ARGOS

SE
DIFF

G

GH L

12

1

AG H L AG H L AG E1 AGE2 G

34256

3

SE
DIFF

G

GH L

78

4

AG H L AG H L AG E3 AG G G

910511 12

6

P1 G P2 G C8 C7 C6C5 C4 C3 C2 C1 G12V 12V

SDM

5V 5V G G

SW 12V

SW 12V CTRL

Logan, Utah

G12V

POWER

IN

CR10X WIRING PANEL

MADE IN USA

WIRING

PANEL NO.

EARTH

GROUND

CS I/O

G12V

INTINT

EXTEXT

BATTBATT

OFF

ON

CHG

CHG

+12

+12

FIGURE 1-2. SAT ARGOS with Enclosure

2. Programming the Datalogger

2.1 Data Packets

Before programming the datalogger, you must determine how much data you
will be sending. Each Argos data packet holds 32 bytes; each data point uses
two bytes. With each data point using 2 bytes, you can send 16 data points in
each data packet. The Array ID is not sent. If you are writing a time stamp to
final storage, don’t forget to include the time stamp as additional data points.

2.2 Data Packet Transmission

The SAT ARGOS can hold up to four data packets. Each data packet is
transmitted as a single message. High reso lution data points are four b ytes, but
high resolution data are not supported by the P125 SAT ARGOS program
instruction.

When you setup your Service Argos account, you must select a message repeat
interval. The PTT will repeat the message at the repeat inter val until a new
message is loaded into the PTT. Most applications will use a 200 second
message repeat interval.

When sending one data packet of 16 data points, the PTT will repeat the data
packet at the repeat interval. When sending two data packets of 16 data points

3

SAT ARGOS

2.3 Datalogger Instruction 125

2.3.1 The Active Storage Area

each, total of 32 data points, the PTT will alternate between each d ata packet.
If you send four data packets, the PTT will send packet one, wait the repeat
interval, send packet two, wait the repeat interval, send packet three, wait the
repeat interval, send packet four, wait the repeat interval, and start over with
packet one.

The datalogger uses P125 to send data to the PTT. All new data, up to 64 data
points, in the active storage area is sent to the PTT. New da ta is all d a ta th at
has been written to the active final storage area since P125 last executed. If
there are more data than 64 data points (4 data packets times 16 data points),
P125 does not send the extra data. The extra data will be sent the next time
P125 is executed. You must not continuously write more data to the active
final storage area than you can send over Argos. The datalogger does not erase
data after it has been sent to the transm itter .

The datalogger has two final storage areas, final storage area 1 (FS1) and final
storage area 2 (FS2). Program instruction 80 is used to set the active storage
area. By controlling where data is written and what storage area is active when
P125 executes, you can keep two separate data files. This can be useful if you
want to collect and store more data than you can send over Argos. FS1 is the
default storage area. The datalogger always defaults to FS1 at the top of the
program table. If you plan to use FS2, you must allocate memory to FS2.
Memory for FS2 can be allocated in Edlog; click on “Options/Final Storage
Area 2”.

2.3.2 New Data

The datalogger must keep track of what data has been sent to the PTT and what
data has not. To track new data, the datalogger keeps several data storage
pointers. The Data Storage Pointer (DSP) p oints to the first location past the
last data value in final storage. The Satellite Poin ter points to the first data
location that was written since P125 last executed. When P125 executes
successfully, all new data is transferred and the satellite pointer is updated and
points to the DSP, or 1 data location past the last data value sent to the PTT.

2.3.3 P125 Result Codes

Program instruction 125 returns a result code to the input location specified in
P125. The result code can be used to determine if P125 executed successfully.
Under certain circumstances the datalogger cannot properly execute P125; for
example, the PTT blocks communications while transmitting. Result codes
can be used to determine if you need to execute P125 again. See Table 2-1 for
result codes.

4

2.3.4 Using Result Codes in the Program

After P125 has executed, check the result codes. If the result code is greater
than or equal to two, execute P125 again. Recheck the result code on the next
pass of the program table. Example Algorithm:

If time to write data

Write data to Final Storage
Execute P125

Use P89 to determine if result code >= 2

If true execute P125

end (P95)

2.3.5 When to Execute P125

Usually P125 is only executed after data has been written to final storage.
While this is not critical, it makes more sense. When P125 sends new data to
the PTT, all data in the PTT is replaced. If P125 is executed when there is no
new data in final storage, P125 returns a result code of 1. Existing data is not
removed from the PTT.

TABLE 2-1. P125 Result Codes

SAT ARGOS

Result Code Code Meaning

0 Normal response, transmitter on line and data packet received
1 No new data in datalogger active final storage area
2 No response from the transmitter, transmitter may be

3 Improper response from transmitter
4 Data packet not properly received by transmitter
5 Transmitter timed out before data packet was received
6 Datalogger serial port not available, probably in use by another

2.4 Program Example

;{CR10X}
;
*Table 1 Program

01: 10 Execution Interval (seconds)

; Load values in input locations

1: Bulk Load (P65)

1: 11 F
2: 22 F
3: 33 F
4: 44 F
5: 55 F
6: 66 F
7: 77 F
8: 88 F
9: 3 Loc [ Start_1 ]

transmitting

device

5

SAT ARGOS

; Load more values in input locations

2: Bulk Load (P65)

1: 99 F
2: 101 F
3: 102 F
4: 103 F
5: 104 F
6: 105 F
7: 106 F
8: 107 F
9: 11 Loc [ Start_9 ]

; If top of the hour, write 16 data point to FS1

3: If time is (P92)

1: 0 Minutes (Seconds --) into a
2: 60 Interval (same units as above)
3: 10 Set Output Flag High (Flag 0)

4: Real Time (P77)

1: 1220 Year,Day,Hour/Minute (midnight = 2400)

5: Sample (P70)

1: 13 Reps
2: 3 Loc [ Start_1 ]

; If top of the hour, transfer all new data to the SAT ARGOS transmitter

6: If time is (P92)

1: 0 Minutes (Seconds --) into a
2: 60 Interval (same units as above)
3: 30 Then Do

7: SCD2/ARGOS (P125)

1: 19 Return Code Loc [ R_Code ]

8: End (P95)

; Check result of P125, if greater than 1 execute P125 again

9: If (X<=>F) (P89)

1: 19 X Loc [ R_Code ]
2: 3 >=
3: 2 F
4: 30 Then Do

10: SCD2/ARGOS (P125)

1: 19 Return Code Loc [ R_Code ]
11: End (P95)
*Table 2 Program

02: 0.0000 Execution Interval (seconds)
*Table 3 Subroutines
End Program

6

3. SAT ARGOS Configuration

The SAT ARGOS PTT must be configured before you deploy it. Service
Argos uses two numbers to track your data through the Service Argos system.
The first number is your Program ID; the second number is your Argos ID.
The PTT can use up to four Argos ID numbers. You must have your Argos ID
number before you can configure your PTT. The Argos ID number and
transmission repetition rate is written to the SAT ARGOS PTT during
configuration.

3.1 SAT ARGOS Power Supply

During configuration, the PTT is powered through the SC532A. For a power
supply the SC532A uses a 12 volt DC wall regulator/transformer or a direct
connection to a 12 volt battery. The SC532A has two internal jumpers.
Jumper P2 supplies 12 volts to pin 8 of the peripheral port. Jumper P4 (Mode)
changes the operational mode of the SC532A. In the “PROG” or program
mode, the SC532A will provide the interface between a computer and the SAT
ARGOS. The SC532 mode is used for storage modules. When using the
SC532A to configure the SAT ARGOS transmitter, configure the jumper P4
for “PROG” and jumper P2 for “ +12V on P8”.

SAT ARGOS

NOTE

The SC532 will not work in place of the SC532A.

3.2 Pttcomm.exe

Included with each SAT ARGOS is a 3.5 inch diskette. The information on the
diskette should be copied to a computer. Load the diskette in the floppy disk
drive and execute “Setup.exe”.

The computer must have a working RS 232 port. Pttcomm.exe is a 32 bit
windows-based program. Run Pttcomm.exe; use “File/Open” to open the
configuration file “Argos.cfg”.

Edit your Argos ID number, or numbers, if you are using more than one.

Scroll down to “Fast Transmission Rep Rate” and “Slow Transmission Rep
Rate”. Enter the appropriate repetition rate for each field. Fast transmission
rep rate is the time between each burst of data transmission (up to 32 bytes
each). Slow rate only applies when using more than one Argos ID number.
Slow transmission rep rate is the time between each burst of data for each ID
number.

In most cases, “Transmission On Time” and “Transmission Off Time” will
not need to be changed. Tran smission on time is the time the transmitter
continues to send bursts of data at the slow and fast transmission rep rates.
Transmission off time is the amount of time the PTT is shut down after the
transmission on time has been completed. Transmission on/off time starts
when the PTT is powered up.

7

SAT ARGOS

3.2.1 Loading the Configuration to the PTT

If you are using more than one Argos ID, the “Number of Additional ID’s”
will need to be changed. Valid inputs of additional IDs are 0, 3, 5, and 7. The
number of additional IDs should be 0 if using 1 ID, 3 if using 2 IDs, 5 if using
3 IDs, and 7 if using 4 Argos ID numbers.

Save the configuration file to a new name. From the PTTComm menu bar,
select File, Save As and save the file to a new name. You may need the
original configuration file at a later date.

Assemble the hardware. You need the SAT ARGOS PTT, the SC532A with
power supply, and two serial cables (SC12). Before you apply power, you
should have a dummy load or antenna connected to the RF output of the SAT
ARGOS. Do not apply power to the SAT ARGOS yet. Make the following
connections:

1) PTT to SC532A using the SC12 ribbon cable.

2) SC532A to the PC using an RS232 cable.

3) Antenna or dummy load to the PTT RF output.

4) Connect AC transformer/12 volt DC supply to power source, but don’t
connect to the SC532A.

After power is applied to the PTT, it will start to transmit. Don’t let the PTT
transmit until you have the configuration loaded. Many times a transmission
from inside a building will be pick ed up by a satellite. To avoid unwanted
transmissions, do not apply power to the PTT before the configuration program
(Pttcomm.exe) is ready.

On the PC, load Pttcomm.exe. Click “ File/pref e r ences”. Set the correct
communications port. Also, set the baud rate to 9600. Everything else should
be left to the default values of: UI Exit string = QQQQQQG, Platform =
WildCAT, Prompt Wait (In Seconds) = 70, Verify data as it is Written and
Simple Mode not checked.

Click on file and open the configuration file “ARGOS.CFG”.

Click on the start button. Apply power to the SC532A; this will power the
transmitter. When the PTT is first powered, it sen ds a start up message out the
serial port. When Pttcomm.exe receives a startup message, the PTT is put in
configuration mode. Pttcomm . ex e will give a message when the PTT and the
computer have established communications. Click on the “Cfg” button to
send the configuration file. In a moment the software will acknowledge the
file was sent. Wait at least ten seconds before you close Pttcomm.exe or power
down the PTT.

4. Satellite Orbit Patterns

At least two satellites are operational at any given time. The orbits carry the
satellites over the North and South poles of the Earth in a sun synchronous
pattern. Orbit period is close to 102 minutes. The satellite foot print is about
5000 km in diameter. At latitudes greater than 75 degrees, each satellite

8

SAT ARGOS

provides coverage each pass. Each satellite pa sses over the poles 14 times a
day providing 28 satellite passes per day. Coverage decr eases with latitude.
At the equator the PTT will “see” a satellite six or seven times a day.

The duration of satellite visibility depe nds on the angle from the PTT to the
satellite. If the satellite passes directly overhead, the satellite will be visible for
about 15 minutes. If the satellite passes close to the horizon, as viewed from
the PTT, the satellite will only be visible for a short time. On average, each
satellite pass is visible for about ten minutes. If using a 200 second repetition
rate, a satellite pass could result in three received messages from the PTT.

Satellite coverage must be considered when planning data collection and
transmission. Given the variability of satellite coverage, hourly data cannot be
expected unless the PTT is located above 75 degrees latitude. The number of
successful data transmissions per satellite p a ss will increase with a decrease in
the repetition rate.

More detailed information rega r ding Service Argos and satellite coverage is
available from Service Argos. On the Web, see http://www.argosinc.com/.
The Service Argos North American office can be contacted by email at
[e-mail] or phone [phone].

5. Antenna Placement

The position of polar orbitin g satellites relative to the PTT will change during
the satellite pass and with each satellite pass. The antenna mu st broadcast
evenly to all areas of the sky. The antenna is omnidirectional. Mount the
antenna vertically. Choose a location with a clear view of the sky in all
directions. Any obstruction between the PTT antenna and the sky can block
data transmission between the satellite and th e PTT.

13904 Antenna

Enclosure houses
the transmitter,
datalogger, and
power supply

FIGURE 5-1. Complete Weather Station with PTT

9

SAT ARGOS

This is a blank page.

10