Joe Kasser G3ZCZ/W3
11241 Fairoak Drive
Silver Spring, Md. 20902
(301) 593 6136
This is a concept demonstration version of a Telemetry Decoding
and display Program for the MicroSat Spacecraft. It is table
driven via the configuration files to allow maximum flexibility.
It contains the following features:
* Real time and Playback modes.
* Capture-to-disk of raw telemetry.
* Link quality measurement.
* Capability to print the raw telemetry as it is received.
* Up to 16 user configurable display pages (screens). You set
the position on the page (width of engineering unit field,
and number of decimal places) that a parameter is displayed
* Wild card page (parameter shows up on all pages).
* Selectable display of Engineering units or Hex byte for each
* Display of raw packets (i.e. STATUS)
* Color changes if a parameter value changed between succes
* Audio and visual alarms if a parameter value exceeds, falls
below or falls outside a preset limit value(s).
* Dumb split screen terminal mode (a la LAN-LINK).
* Customizable colors, PC to TNC baud rate, data parity and
* Default spacecraft configuration files.
* Time of day clock display (in HH:MM:SS format)
In the telemetry processing part, only the quadratic equation is
hard coded, the coeficients are table driven from a configuraton
file. In fact the contents of the configuraton file are as fol-
Selected or default display page
Number of display pages (maximum = 16)
Then follows the page definitions, as in for example;
SPACECRAFT HOUSEKEEPING, 30,31
PAYLOAD, 30, 31
BATTERY STATUS, 30, 30
the number above the page definitions must be set correctly.
For each page:
The next set of items is the Telemetry parameter configurations
(maximum = 64). Typically each row looks as follows:-
00,Rx E/F Audio(W):,+0.000,+0.0246,0.000,V(p-p),2,11,1,6,1,0,0,0
01,Rx E/F Audio(N):,+0.000,+0.0246,0.000,V(p-p),2,11,32,6,1,0,0,0
For each telemetry parameter:
hexadecimal channel number (2 bytes, e.g. '0F' )
Descripion text string (e.g. '+Z Array Temp.')
Equation Coefficient C
Equation Coefficient B
Equation Coefficient A
Units text string (e.g. '.C')
Display page number
Display page row
Display page column
Display width for Engineering Units
Number of digits after the decimal point
Limit check flag (0 = do nothing, 1 = check below low limit,
2= check above high limit, 3 = check
for [below low limit] or [above high
Low limit value (e.g. -4.00)
High limit value (e.g. +10.6)
A line with an '*' as the first character terminates that
packet types are set as follows:-
name of UNP address (e.g. WASH, BCXRT)
Display page for the contents of the packet
Display page for the cumulative count of the packet type
Typical entries are as follows:
WASH, 0, 30,4, 1, 0, 5, 1
TIME, 0, 31, 1, 1, 0, 5, 12
STATUS, 0, 29, 2, 1, 0, 5, 24
BCRXMT, 0, 28, 3, 1, 0, 5, 37
TLM, 99, 31, 3, 1, 0, 5, 50
These also terminate with an '*' character.
Limits are only checked for parameters being displayed (in Engi-
neering units). With this approach, you can set up different
pages for different on-board subsystems, you can also set up
different display pages of the same parameters for daylight,
darkness and terminator crossing passes, with different limit
values to draw your attention to changes.
The link quality part allows the following to be done. You can
define which of the packets you want to display/count (If you
just want to count them and not display them, set the page value
to 99). You can then view an incrementing count counter each
time a selected packet is received. You can also display the
contents of the STATUS, WASH or BCXRT packets in any display
My version is set up to display those packets as wild cards (i.e
will show up on all pages), and then display several temperatures
and solar cell array currents.
IBM PC or clone with 256k memory.
TNC of some kind, I've tested it with a TNC2, a KAM and a PK-232
The program DOES require that the telemetry be received, and
captured-to-disk with the packet header on a different line to
the contents of the packet (HEADERLINE ON). I also suggest that
you turn the date/time stamp on so that when you get Revision
1.00, you will be able to playback your data and extract selected
values and their corresponding time codes into a file that can ne
read into your spreadsheet program for further trend analysis.
A typical display is shown below.
PHT: uptime is 046/12:38:33. Time is Tue Jan 30 03:07:27 1990
80 00 00 89 B0 18 DD 02 00 B0 00 00 B0 00 00 00 00 00 00 00
vbat= 10.864 vlo1= 10.540 vlo2= 10.040 vmax= 11.540 temp= 6.661
wash addr:2a80:0000, edac=0x70
WASH 28 TIME 22 STATUS 21 BCRXMT 2 TLM 17
+Z Array Cur :-0.011 A +Z Array Temp : -6.7 C +Z Array V : 0.1 V
-Z Array Cur :-0.017 A +Y Array Temp : 10.9 C
-Y Array Cur :-0.012 A Baseplt Temp : 6.7 C BCR Load Cur : 0.164 A
+X Array Cur :-0.013 A Array V : 9.8 V
-X Array Cur :-0.011 A +5 Volt Bus : 4.9 V +8.5V Bus : 8.5 V
+10V Bus : 10.8 V 8.5V BUS : 8.4 V
TX#1 RF OUT : 0.0 W +8.5V Bus Cur : 0.053 A
TX#2 RF OUT : 3.7 W +5V Bus Cur : 0.208 A BCR Input Cur : 0.191 A
BCR Output Cur :-0.017 A
Bat 1 Temp : 6.7 C Bat 2 Temp : -20.6 C
IR Detector : 0 Counts
BCR Set Point : 134 Counts
TLM.SYS file format
The contents of the TLM.SYS file are as follows:
Your callsign (e.g. G3ZCZ)
Default configuration file) (e.g. Dove)
station latitude (e.g. 35.00)
station logtitude (e.g. 74.00)
station asl. (e.g. 100)
capture-to-disk file (e.g. dove.RUN)
playback file (e.g. dove.run)
PC serial port (e.g. 1)
PC serail baud rate (e.g. 9600)
data bits (e.g. 8)
Stop bits (e.g. 1)
parity (e.g. 0)
status (top) window color (e.g. 79)
Telemetry Page color (e.g. 14)
outgoing window color (e.g. 14)
incoming window color (e.g. 30)
prompt window color (e.g. 15)
alarm window color (e.g. 15)
bottom window color (e.g. 79)
Emphasis color (e.g. 14)
prompt color (e.g. 14)
option color (e.g. 78)
parameter changed color (e.g. 95)
parameter limit exceeded color (e.g. 14)
Some typical color combinations are
The following function keys are active:
FK 1 capture to disk
FK 2 type of display Engineering Units/Hex Byte
FK 3 select display page
Alt-B send a 'break' to the TNC, interactive mode only.
Alt-P Printer on/off
Alt-S Sound on/off
left arrow decreases playback speed
right arrow increases playback speed.
This version as I mentioned above is a concept demonstration
version, and contains a few cosmetic display bugs. I expect
(but don't promise) to put out Revision 1.00 with more features,
and proper documentation, sometime in March 1990. This program
is not in the public domain but may be copied and passed on. If
you would like a copy of Revision 1.00 which will be released as
shareware, send a FORMATTED disk and sase to
Joe Kasser G3ZCZ/W3, 11241 Fairoak Drive, Silver Spring, Md.