Version 11/01
GPS FLIGHT DATA RECORDER
ZANDER / SDI GP 941
MANUAL
content:
1. Introduction
2. Installation into glider
3. Turning on the GP941
4. Connecting GP941 to PC
5. Entering data from glider computer SR940
6. How to use GP941
7. NMEA Output
8. Technical data
9. Wiring diagrams
10. Pin assignments of connectors
11. Calibration chart for altimeter of GP941
Annex: FAI approval document
Warning:
The recorder box must not be opened! A security feature will inhibit any valid recording after
box was opened! The standard two year warranty is expired when box was opened!
2
3
4
5
7
8
10
11
12
14
15
16
GP941E 11/01 02.11.01 1
1. Introduction:
The flight data recorder GP941 (= FDR, recorder) consists of one housing with these functions
inside:
GPS receiver
barometric altitude sensor
electronics for recording and storing data
microphone circuit for gliders with engine
a Lithium battery 3.6V for data retention
a 9V battery for data transfer between recorder and IBM compatible computer (= PC)
Externally connected are GPS antenna, 12V / 120mA power supply, a marker button and the connection to SR940 glider computer.
The GP941 is intended to be used as a part of the glider computer SR940 system; together with this
glider computer the GP941 has these additional features:
GPS data transfer to SR940
automatic photo sector signal to GP941
declare and transfer a task from SR940 to GP941
waypoint lists and routes can be entered into recorder and brought to the glider, where these
informations can be transferred to SR940
saving and restoring configuration data of SR940
transfer of additional data from SR940 to recorder which are included in the stored flight data:
indicated airspeed, wind information, next waypoint selected.
If the glider computer SR820D is used together with the GP941, there will be only a display of GPS
information. All other functions mentioned for the SR940 are not available with SR820D.
For glider computers from other manufacturers or a palm PC this function can be used:
NMEA data output with GPS data and barometric altitude
The GP941 also can also be used as a stand alone system without any glider computer connected.
But in this configuration there is no information on reaching waypoints. To check GPS function of the
recorder, this feature can be used:
output for external light emitting diode (LED) mounted within the instrument panel
GP941E 11/01 02.11.01 2
2. Installation into glider:
The GP941 recorder should be fixed to the glider, so that it can be removed easily.
If a glider computer is used with the recorder it is not necessary to see the blinking LED or hear the
beeper of the recorder during flight. GPS function will be checked with the display of the glider computer. Without glider computer the blinking LED should be visible or an external LED should be
mounted within the instrument panel.
For gliders with engines there is no special mounting necessary, as a microphone within the GP941
will record the noise level which is nearly independent of place for the recorder.
The power supply to the recorder is switched by a safety switch which must be lifted when changing
between on and off. The safety switch is recommended, as a flight data record will be unvalid if the
power supply for the GP941 is off for more than one minute.
To enter a special mark into the recorded flight data there is a marker pushbutton for the instrument
panel. Pushing the marker button also adds 10 fixes of 1 second interval to the recorded flight data.
For normal operation this marker button is not necessary.
To make the power supply for the recorder safe, it is recommended to use always two batteries with a
switch to change from one battery to the other. The batteries mostly used in gliders can fail or deteriorate at any time without warning. Besides this you should expect during competitions or when travelling, that the main power may break down during night which leaves you with partly charged batteries
in the morning.
The GPS antenna is mounted horizontally. The antenna must have a undisturbed view all around.
Metal, carbon parts and human body will hold off GPS signals from the satellites, glas fiber and acryl
glas will not. A good place for the antenna is just under the cover of the instrument panel.
For cabling see cabling diagrams at the end of this manual.
GP941E 11/01 02.11.01 3
3. Turning on the GP941:
After turning on supply power to the recorder there is an acoustic signal from the recorder to show
that it is operating:
2 x beep = flight data recorder ready for recording
The red light (light emitting diode, LED) shows:
... = no GPS reception
After about 2 minutes (glider away from buildings, GPS antenna unobstructed) the light emitting diode
changes to:
... = GPS reception
Checking the GPS mode of the recorder can also be done by pressing the marker button:
press marker button; reply: 1 x beep = no GPS reception
press marker button; reply: 2 x beep = GPS reception
With a glider computer connected, the checking of GPS operation is done by watching the displayed
GPS information: if GPS information is present then the recorder is functioning properly.
As soon as the recorder is supplied with power, data recording starts. Every four seconds a point is
stored. Without GPS reception only time and barometric altitude are recorded, with GPS reception
position and GPS altitude are recorded too. A record ends by turning off the power and leaving it off
for more than 5 minutes or by establishing PC connection.
Short power cuts will not end a record.
Important:
The GP941 records always when power is applied; recording is active on the ground as well as in the
air, independent of speed or altitude.
During PC connection there is no recording.
Recording within the GP941 is done in that way that the last 50 hours of recording time are always
kept in the recorder. Flight data cannot be deleted, but the oldest flight data are overwritten by new
flight data.
Begin and end of any recording are stored in a separate list within the GP941. This list will keep the
last 200 records. With GPS reception, times for takeoff and landing are automatically inserted into
this list (first takeoff and last landing). This list can be read as flight log from the recorder to PC.
If the GP941 was not used for more than 4 month or the position has changed for more than 500km
compared to the last recording, it may take a longer time until GPS reception is available. After first
reception the GP941 should be kept running for more than one hour, so that the GPS receiver can
adapt to the new conditions. This first recording should not be used for FAI or competition pur-
poses.
GP941E 11/01 02.11.01 4
4. Connecting GP941 to PC:
The PC used must be an IBM compatible PC:
WINDOWS 95 or later for Windows programs
DOS 3.0 or later, 512 KB memory for DOS programs
Most of the programs on the CD-ROM delivered with the GP941 are Windows programs; there are
some DOS programs for special use.
First the Windows programs must be installed on the PC. Information on this can be found in the text
file ReadMe.txt on the CD-ROM.
Before starting the GP941 program all other programs which use the COM port must be terminated.
This is especially important for palm PC programs or organizer programs which may be running
without showing any sign.
Use the connection cable 9-9 to connect the COM port with the GP941. The PC connector is the 9 pin
socket besides the LED and the beeper. During PC connection the GP941 is supplied by the 9V battery within the recorder (besides the connector for power supply). This battery allows up to 20 hours of
data transfer before it must be replaced.
PC connection is also possible with 12V power supply connected. Then the 9V battery is not used.
Important:
Use only a standard 9-pin extension cable between GP941 and PC!
The old data cable used to connect old SR940 and SR820D to a PC cannot be used!
The programs for GP941 are continuously updated, so it is not possible to give an accurate descripion
on how to use the programs. At date April 2001 this description may be helpful:
Before using GP941 for flight data recording, the name and glider information should be entered into
the recorder:
To enter name and glider id into recorder:
Start program WinZAN; select COM port, language and press o.k. button
Select subprogram WinGP.exe from the list and start it;
click on LapTop symbol
special / enter personal data
enter name using standard ascii letters
write
end Win GP.exe
To read flight data from recorder:
start WinGP.exe
click on LapTop symbol
flights / read records
select flight with up and down arrows on the right
read / save flight data to a folder of your choice
ZAN files are stored
end WinGP
To show flight:
select WinFDR32.exe from list and start it
click on folder symbol
open flight data from the folder of your choice
recorded flight data will be displayed
GP941E 11/01 02.11.01 5
Important for FAI flights:
WinGP can also store flight data in IGC format or can convert ZAN files to IGC files. However
these IGC files cannot be used for FAI purposes anymore. To get IGC files as required for FAI
purposes the ZAN files produced by WinGP must be converted to IGC format by DOS program
CONV-ZAN.EXE. In Windows this can be done easily by dragging the ZAN file over the CONVZAN application.
With WinGP you also can write waypoint lists, edit them, transfer them into GP941 or read them from
GP941. You also can set up routes after having opened a waypoint list.
(Attention: due to a program bug in WinGP, the last waypoint of a list cannot be used for routes! To
avoid this problem, enter the last waypoint twice at the end of the list and use only the one before last
for routes.)
A short description of the waypoint and routes organization for the glider computer SR940:
A waypoint list may have up to 990 entries. A route may have up to 20 entries selected from this list.
The SR940 can store and use up to 8 preselected routes. These 8 routes as maximum are called a
set of routes. The GP941 can store 5 sets of routes. When reading routes from GP941 to SR940 the
set number is entered and one set is transferred to SR940. For setting up routes for GP941 and for
using routes with SR940 the same waypoint list with the same waypoint numbers must be used. Routes only store waypoint numbers, not the names.
Up to 6 different configuration settings for SR940 can be stored within the GP941 and can be recalled
by SR940, so that several pilots can fly on one glider using their own SR940 configurations. Settings
1 to 6 can be read by SR940, but only settings 1 to 3 can be written from SR940 into GP940. With
WinGP these settings can be repositioned.
If a waypoint list is opened, a task can be declared with WinGP according to FAI rules. The declared
task with turnpoint information, time of declaration and date of the declared flight will be added to the
flight data of the next flight data record.
Before reading back a flight declaration just after writing, you have to wait for 6 seconds.
(Attention: due to a program bug in WinGP you cannot read back a task after writing. Instead you
have to end WinGP and start it again; then you can read back a task.)
Note:
Tasks must be declared always in this sequence: takeoff point, departure point, turnpoint(s), finish
point, landing point. If takeoff point and departure point or finish point and landing point are the same,
these points must be entered twice.
It is easier to enter the task with glider computer SR940.
Important:
all entries made into GP941 for SR940 purposes do not influence the recording of flight data; the
GP941 is used for transport of data to the glider only. Entered waypoint list and route do not influence
the task declaration within GP941 and are not used for information when rounding turnpoints.
GP941E 11/01 02.11.01 6
5. Entering data from glider computer SR940:
If the recorder is connected to glider computer SR940 and if the SR940 is equipped with the correct
program version, data can be exchanged between recorder and SR940.
The SR940 has a special text page to communicate with the GP941; this text page has several submenues:
21 : FD - Re c or d er
1= t as k
fo r 21 . 05 . 96
00 = ta k eo f f a t :
34 7 =T A NN H AU S EN
de c la r e f l ig h t?
= N O
The route cannot be programmed on this text page 21; however it is possible on this page to check
the correct sequence of waypoints by advancing the two digit leg number.
When a task is declared according to FAI rules, the day of the intended flight must be entered together with the task. A task declared via SR940 is only valid for the same day (the date visible on
text page 21).
If cursor is moved to NO and toggle +1 is pressed, then YES is shown and the task is written into
GP941. Within the recorder the task data get a time and date stamp using the internal clock of GP941
to mark when the task was declared. At the same time the task is copied into the flight data.
The route selected on text page 11 of SR940 can be transferred to
GP941 as a declared task. This tranfer must be done before takeoff
to be valid. The turnpoints are selected on text page 11 only; selection
of turnpoints must be done according to FAI rules in this sequence:
takeoff point, departure point, turnpoints, finish point, landing
point. If takeoff point and departure point or finish point and landing
point are the same, the waypoint name must be entered twice each.
So an out and return flight consists of 5 waypoints.
After declaration of the task, the recorder and SR940 may be turned off. When power is applied again
to the recorder, the task data entered last are copied into the flight data record just when recording
starts.
A declared task can be changed as desired up to takeoff time; after takeoff it is still possible to enter
tasks but these declarations are unvalid, as the time of declaration is later than the takeoff time.
Attention: when recording starts, the task which is stored within the GP941 is written to the flight data
record. But if the task is old, the day of the intended flight will not be the day of the actual flight; so an
old task is unvalid.
The following submenues allow transfer of waypoint lists, routes and configuration data between
GP941 and SR940. When saving and restoring configuration sets it should be noticed, that sets no.
1...6 can be read to SR940 but only sets no. 1..3 can be saved from SR940 into GP941. So sets no.
4..6 cannot be overwritten by SR940, but sets 1..3 must be brought to 4..6 using a PC program like
WinGP.exe
2 1 :F D -R e co r de r
2= r ea d WP s :
F D R s t ar t := 0 01
F D R e n d: = 1 00
to SR : =2 0 0
=N O
21 : FD - Re c or d er
3= r ea d ro u te s
fr o m F D R:
se t no . =1
=N O
2 1 :F D -R e co r de r
4= r ea d co n fi g .
f r om FDR :
se t no . =1
=N O
2 1 :F D -R e co r de r
5= w ri t e W P s:
S R st a rt : =0 0 1
S R en d : =1 00
to FD R := 4 00
=N O
GP941E 11/01 02.11.01 7
2 1 :F D -R e co r de r
6= w ri t e c o nf i g.
t o FD R :
se t no . =1
=N O
2 1 :F D -R e co r de r
7= w ri t e n a me #1
to F DR :
HE L MU T MU E LL E R
=N O
If program version 2005 or later is loaded into SR940 and GP941 has version 2.04 or later, then the
name of the pilot can be written from SR940 to GP941. Up to three names are stored within SR940
and can be selected by number #1 to #3. Transfer of name should be done before takeoff, as this will
begin a new flight data file within GP941.
6. How to use GP941:
Here are some suggestions for pilots and competition organizers:
Flights during central competitions:
Before takeoff waypoints must be loaded into SR940 / SR920D. The coordinates of the waypoints
must be exactly those which are used for the given tasks. Use only waypoint lists provided by the
competition organizers!
Enter name, competition class and competition number into GP941.
Select the correct GPS alarm (Photo sector or circle) at glider computer SR940.
The recorder must be turned on in time before takeoff, so that GPS reception is already active before
takeoff.
In the air any point can be stored acurate by one second when the marker button is pressed. These
marks are in addition to the standard 4 second fix interval. Pressing the marker button also initiates a
sequence of 10 more measurements with 1 second interval.
If SR940 announces entering the photo sector or circle, an automatic mark signal is transmitted to the
recorder, which adds 10 additional fixes with 1 second interval to the recording. This automatic mark
signal is transmitted only once when entering the photo sector or circle.
After landing the recorder is turned off and is removed from the glider.The competition organizers will
read the flight data from the recorder and evaluate the flight.
Flights in a decentralised competition:
Before takeoff there should be done a written declaration signed by an official observer. This flight
declaration must contain:
date of the intended flight
full name of the pilot
type of glider, competition class, glider registration number
used GNSS flight data recorder: manufacturer, type, serial number
The declared task can be written on the same paper or the flight declaration is marked with task as
written into flight data recorder. If the task is done by writing then the task within the recorder should
GP941E 11/01 02.11.01 8
Loading...