1.
I have some questions about Peter Zander's system, where can I go
Probably I can answer them all; e-mail me at kpt9@wxs.nl.
If necessary we can
contact Peter at pzander@compuserve.com.
2.
What is the basic PZ system.
The basic PZ system consists of the 9900
series SR940 flight computer with an
analog or
digital Vario/Speed-Command indicator and the coupled new GP941 GPS/Datalogger unit.
However in the summer of 2003 this has been
changed to the new ZS1 flightcomputer with
the ZS1R digital vario-indicator. The GP941
stays the same (is quite new alresdy) as well
as some optional items.
The GP941 and the new ZS1 and ZS1R can be
seen at http://home.wxs.nl/~kpt9/Rozander.htm
The SR940 flight computer has a large dot matrix screen with text and graphic pages.
Specific features are the moving map
displays for next waypoint presentation, nearest
airports, nearest specific positions and
control zones (with alarm function). The ‘next
waypoint’ presentation has an automatic
zoom function and a visual “fly over start and
finish line” and “fly into or around the
waypoint area” feature.
Wind calculation during circling and also
during straight flight is available. Average
wind component calculation over part of a
task, including one or more waypoints is
available. NMEA-0183 data are available for
external use. A special cable with 5V power
supply can be provided. Simulation mode
(IAS, Vario and GPS)is available.
The
GP941 GPS/Datalogger is a rigid
unit and FAI certified of course. Waypoints can be
loaded at home into the unit and
transferred to the SR940 flightcomputer at the airfield
(no laptop required). The small GP941 can
work as a solo unit; only 12 V supply and an
antenna are required. An NMEA-0183 port is
available to provide data to e.g. a Pocket-PC.
More details on the above systems can be
found on the home page of Peter Zander at:
http://ourworld.compuserve.com/homepages/pzander/
WinZAN11, containing the latest
version of basic SR940 and GP940/941 software and
additional matters is available at: http://ourworld.compuserve.com/homepages/pzander/
The older version of WinGP is not valid
anymore and must be replaced by WinGP02 included
in the WinZAN package. Latest manuals
are also included in the WinZAN package; the
SR940 manual can be viewed here.
3.
Can I update myself the SR940 program
and data bases when new versions are available
In the 9900 series SR940, the operating
program and databases for control zones, airfields
and waypoints are stored in the Flash Rom of the unit. They can be
updated any time using
your own laptop or PC and program WINZAN
that comes with the system. New versions of
the program or data bases are avaible for
free on the Internet. Certain new
binary control
zones files (like de0103.azb) are available
for free on Peter’s home page. Others may be
ordered from Hans Trautenberg. Data bases
designed by yourself in ascii format (control
zones, airfields and waypoints) may be used
as well of course.
A previous SR940 program version is
prg2004*.prg (in German, English and French). A new
program version having Dutch rather then
French as a third display language is NL2005.prg
and can be downloaded now at: NL2005.prg. Latest versions of the SR940
program can be found
on Peter’s home page. Contact me for more
details.
Databases suitable for uploading into the
9900 series are e.g. holland.wpz
(waypoints),
eu9905.wz
(airfields in europe), de0103.azb
(airspaces in Germany) and ned9804.az
(airspaces
in Holland). Other waypoint databases (.wpz
files) can be found in my XCPAS Cross-Country
Planning and Analysing Software package at http://home.wxs.nl/~kpt9/xcpas.htm.
4.
What are interesting additional
features to the basic system
- compass
option to calculate wind direction
and strength also in straight flight
- stick
grip with buttons and switches to remotely control the SR940 unit (+ PTT
switch)
- rotary
switch to quickly scroll through the waypoint list or increase/decrease
numbers
- data
cable (free) to connect your laptop or PC to the SR940 and GP941 units
- NMEA-183
interface box to connect your own gps receiver to the SR940 unit
- NMEA-183
cable with 5V power supply for use with either a Pocket-PC or a laptop
- special cable with
mini-connector to connect the NMEA cable to an iPaq Pocket-PC
- accelerometer to provide the g-load to the stall warning feature of
the SR940
- 9900 series motherboard with flash
rom to upgrade your somewhat older SR 940
- moving map display with high
resolution for use as second indicator, available in 2004
- V/S indicator and LCD display;
new 60/57 mm high resolution indicator, available in 2004
5.
Can my somewhat older SR940 unit be
upgraded to the 9900 series
Yes no problem. A new computer board must be installed + new software;
contact me or Peter about this. New
features can be found at PRG9905E.htm.
6.
Can my older SR820D unit be upgraded
to a SR940 9900 series unit
No, not anymore. Peter is out of parts to
do so.
7.
Is it possible to back up the GP941
with another GP941
Yes no problem I have a special so called Y-split cable with data switch for
that.
Gives full backup with data flow to the
SR940 from either unit.
Contact me if you are interested.
8.
What is a recommended order of page
texts (9 pages, selection from 26 texts)
page 01, text 26:
departure/turnpoint/finish display (with automatic zoom in feature)
page 02, text 14: nearest airfields display
(with "go to" function, moving map display)
page 03, text 17: airspace displays with
selectable map size (with alarm function)
page 04, text 16: nearest positions
displays (4 options with "go to" function, mov. map)
page 05, text 12: ETA page with total
length of route, estimated time of arrival, etc.
page 06, text 19: statistics page with
flight info
page 07, text 20: flight log page with info
on all recent flights
page 08, text 21: FD recorder page for
communication with GP941 (declarations, waypoints)
page 09, text 09: GPS page to observe
proper operation of GPS receiver in GP941 unit
9.
The deviation from glidepath makes no
sense, what do I do wrong
No waypoint is displayed on the flight page
or one of the two info lines shows incorrectly
"remaining distance".
10.
My S/V switch on the stick or flap
mechanism does not work anymore
The most right switch with the white cap
on the SR940 unit must be in the "A"
position.
On your request I can change this switch
to a toggle having a Volume function.
11.
I like to do some training with the
system before actual flight
No problem, the SR940 has a simulator setting for IAS, Vario and
GPS. Simulation can be
practiced at home or in the glider.
12.
When GPS is not available is the
SR940 then still usable for X-Country flight
No problem, the flight computer will then (continue
to) work in the D-mode using elapsed
time and speed (IAS) while in straight
flight.
13.
How is the wind calculated by the
SR940
The SR940 calculates wind strength and
direction during circling using GPS
data and also
during straight flight when the compass option is available. In the latter
case the
effect of wind on “deviation from
glidepath” can be set to automatic. Else the wind
component to the next waypoint can be
taken over manually during circling, or in the
direction of flight while in straight
flight (compass option off).
14.
Can the effect of wind be implemented
with one or some turnpoints still to go
Yes, let one of the two info lines on the flight page show
"remaining distance".
15.
For a X-Country flight, how do I set
waypoints of a task
Always this order: starting place
(airfield), departure point (airfield), turning points,
finish point(airfield) and landing place
(airfield) (so six points for a
standard
triangle).
Before flying to the departure point select leg 00 (airfield) to gain height, wait,
enjoy yourself, etc.
Total task distance can be seen at the ETA page (text 12), provided that leg
00 is
selected and no other waypoints are given
before the starting place and after the landing
place.
For a local
flight use the points starting place (airfield) and landing place (airfield)
and select leg 00 to avoid the “in
observation zone” sound.
16.
I like to fly back to a wonderful
blue thermal
No problem, use the buoy function to mark the place. Distance and heading to this buoy
is
then indicated on the flight page. Correct
for the wind when flying back to the thermal.
17.
I heard something about a centering
aid
Yes correct, the SR940 gives a clear beep when better centering gives a
better climb rate.
At the beep you have to fly a few seconds
straight and then bank again; most pilots use
it especially after long flights when
concentration becomes a little less usually.
Go to settings, position 14 to activate
the centering aid.
18.
Can I show waypoints on a graphics
screen in the same way as nearest airfields
Yes no problem, mark the waypoints with
"*" (pos. 36 in the waypoint list).
All waypoints marked with “*” will now
show up on the nearest position pages.
Other features, like landing fields,
mountain passes, thermal spots etc, may be marked
with one of "1,2,#" and shown
separately.
19.
Is a stall warning available
Yes, just order the g-meter and set the stall speed for 32 kg/m^2 wing loading. The
warning, an awkward sound, comes up taking
into account actual static wingloading
(e.g. 42 kg/m^2 with water in the glider)
and g-force as experienced during circling or
pull up and pull down movements during
straight flight.
20.
The deviation from glidepath is not
correct when I use the “remaining distance” option
Probably you forgot to specify the landing place as the last point of the
task (see
14. above). In the “remaining distance”
option, the last but one point of a task is taken
as the finishpoint. So a finishpoint and a
landing place must be specified seperately.
21.
How is deviation from glide path
calculated
Total glider height Ht = static height Hs +
kinetic height Hk.
Static height is actual height H over the
next waypoint (landing field).
Kinetic height relates to speed over 123
km/h (34.3 m/s), below which it is
assumed that the speed of the glider is to
low to gain any height from (safe limit).
As a formula: Ht = Hs + Hk = H +
(v^2-34.3^2)/2g (v is speed in m/s, g = 9.8 m/s^2).
Glide path height Hg = heigth required to
get to the next waypoint or landing
field. So Hg = Dist/e, where Dist
is distance and e is actual glide ratio (dependant on
Mc setting, polar type, specified e at 32
kg/m^2, wing loading and wind component).
Deviation from glidepath Hd = Ht – Hg,
or Hd = H + (v^2-34.3^2)/2g – Dist/e.
Realise that when already “in gliding
range”, Hd can become negative for more then one
reason (usually however for a to high Mc
setting). Realise also that during the glide,
rising and falling air as well as
variations in the wind component will influence Hd for
better or worse.
22.
How can I analyse my flights
Use the free analysing program Winaw.exe,
that comes with Peter’s system (part of
the WINZAN
package) or use the XCPAS
package available for free on my home page.
23.
Transferring data to and from the GP941 is difficult or impossible
The
voltage of the internal battery of the GP941 may be low. Connect the charger to
the
unit
while transferring data to and from the unit. The internal battery must be
replaced.
24.
For Total Energy I use a pneumatic probe but compensation is not ideal
You may try to trim the probe using
additionally “the electronic compensation” option
while TE compensation is “with probe”. TEC
values between –0.25 and +0.25 can be tried.
The special functions option must be
switched on at text page 22 (standard setting = NO)
to maintain the additional electronic TEC
value.
25.
Is it possible to compare bearings on the display with those on task
sheets and maps
Task sheets and maps, usually show true
bearings and true radials. However because of
aviation standards, all directional
information of the SR940 unit is presented in magnetic
degrees. Variation is added to true values
calculated, to achieve this. However for the
purpose of accurately passing over a
boudary line of an AAT sector, true bearing to a
selected waypoint is available now at the
last info line. This line can be selected as one
of the two info lines on the flight page.
26.
What languages are available for the operating program of the SR940 unit
The operating program *.prg can run in 6
different languages, i.e. German, English,
French, Dutch, Danish and Finish. The
Dutch version of the latest program version (also
containing the German and English options)
is NL2005.prg and can be downloaded here:
NL2005.prg. Select the option “French or other
language” when running WinSR940, to upload
the Dutch version into your SR940 unit.
See also item 3 above.
27.
Can I be sure that the difference between departure and finish altitude
is less then 1000m
Since program version prg2004.prg pressure
altitudes measured by the flightcomputer SR940
as well as by the GNSS data recorder GP941
(version 1.25) are displayed on text page 5.
Both altitudes can be set to airfield
elevation (MSL) before take off.
The SR940 pressure sensor “sees” accurate
static pressure and is used for precise
glide path calculation.
The GP941 unit “sees” cockpit pressure, so
the GP941 altitude may slightly deviate from
the SR940 altitude. GP altitude can be
selected on text page 5 for display of all
altitudes, e.g. as elevation over ground
(Alt2) on the flight page. The GP941 unit records
this altitude plus a pressure sensor off
set. The off set cancels out in the analysing
proces of the recorder trace.
28.
Where can I see the total task length
After a task has been specified on text
page 11, go to leg no 1. Then go to text page 12
and the total length of the task is
indicated. Task done will then be 0 km. The task must
be corretly defined as: airfield,
startpoint, waypoints, finishpoint and airfield and
nothing less or more in front of or
following the task.
29.
Where can I find the coordinates of my current position
Especially after an outlanding it is
important to know the coordinates of the current
glider position. To find out, go to the
waypoint list (text page 10). Position 0999 will
show the current coordinates.
30.
After some years now, some push buttons on my stick grip tend to stay
pushed in
Yes, this may happen due to some grease
transferred from your fingers to the stick grip in
warm conditions. Clean the buttons with a
little bit of “cockpit spray” on a soft cloth,
especially the slits between the buttons
and the stick grip body. You may additionally use
small pieces of paper “side ways” to
remove the grease out of the slits. The spray can be
obtained from shops selling car supplies.
31.
In my glider the 12V to 5V chopper converter to feed a Compaq is noisy on
the radio.
In about 30% of the cases a chopper
converter in a glider generates to much noise on the
radio. Usually this is caused by a summation of noise sources combined
with a specific
layout of the cabling in the glider,
sensitivity of the radio etc. Contact me if this
applies in your situation. Then we can
have a closer look at your system.
32.
For some reason I see very large values of altitudes after downloading my
GP940 logger
This is quite possible due to a software
bug in WinGP, the download program in Windows.
The problem occurs with initial negative
values of the altitude are recorded on the ground.
Use the new WinGP02 version or the DOS
version Data-Zan.exe to avoid this problem.
33.
It looks like the SR940 produces some extra noise on the radio; what can
I do
Contact me or Peter. An EM shield must be
placed on the backside of the display board.
This is standard now for all new units and
is available as an upgrade.
34.
Is it possible that my radio interfers with the gps receiver
Recently it has been found that the 12th
harmonic of 131.275MHz and the 13th harmonic of
121.175MHz, or frequencies very close to
that may interfere with the GPS L1 frequency
of 1575.42MHz. Especially in gliders with
a 5W transmission power, GPS reception may blank
out when the PTT button is pressed using
these kinds of frequencies. GPS reception is
regained within seconds after release of
the button.
This is a generic problem and valid for
all radios and GPS receivers. Special filtering
and shielding measures seem to have some
positive effect; the best solution at the moment
is not to use the specific VHF
frequencies.
35.
During straight flight my wind(component) calculation is not accurate
An airspeed correction table (4 values)
can be made up. This can be done using option 15
of the SR940 configuration settings and
the methods described by Peter Zander in his
manual.
However you may try a first order approach
by changing the CAS value in option 15 a few
km/h’s and fly with and against the wind
at 150 km/h IAS a couple of times. At the right
CAS value (e.g. 160 km/h) the indicated
wind(component) when flying with the wind
and against the wind must be the same in
magnitude. If you have found a proper CAS at
150 km/h IAS, then use the same relative
CAS values for 90 (e.g. 96), 120 (e.g. 128) and
180 (e.g. 192) km/h IAS.
36.
Potential Temperature (hu?)
Tpot = Potential Temperature = the temperature a parcel of air would have if brought down
adiabatically at “ground level” (1000 mb level). Very roughly Tpot = Th +
0.01 * h, where
Th = local temperature and h = height in m
above the “ground level”. Th is measured with
temp. sensor and must “see” ambiant
temperature. Can be displayed at one of the info lines
of the SR940 flight page.
Used to find thermal activity at ground
level while flying at height through uneasy
air which may have risen from the ground.
37.
Connecting a PDA for moving map display
NMEA-0183 output is provided by the SR940
9900 series flightcomputer via the 15 pin
connector at the back of the unit and via
the 9 pin female connector of the new GP941
GPS/FDR. Pin assignments are given in the
GP941 manual.
The standard $GPRMC line of the NMEA
protocol contains time, coordinates, etc. The
additional $PZAN1 line contains altitude
and serial number of either the SR940 or the
GP941 unit (see specs down below). The
serial nr. may be needed for the software on the PDA.
Cabling and a 12V/5V converter are available
to connect a flight computer or logger
to an iPaq 39xx, 54xx or 22xx. Contact me
at kpt9@wxs.nl for that.
Pocket-PC’s running under Windows-CE are
suitable for moving map display using e.g. the
Winpilot program with its attractive
geographical maps.
Some files suitable for uploading into
these programs are terletmd.dat
(waypoints and
airfields)and terlet00.dat (airfields only).
38. Some terms explained
QNH = altitude over mean sea level (set
subscale at valid msl pressure)
QFE = altitude over the field (set alt. to
zero at the airfield)
FLT = altitude relative to the 1013.2 hPa
pressure altitude level (subscale at 1013.2)
TEC = Total Energy Compensation (Pstat –
Pdyn = constant when changing speed for
height without energy loss and vice versa)
Vgps = GPS ground speed (subsequent gps
positions devided by time interval)
IAS
= indicated airspeed (from dynamic pressure = total pressure – static
pressure)
IAS
= constant x sqr(Pdyn)
CAS
= calibrated airspeed = IAS x Cf where Cf is correction factor
TAS
= true air speed derived from CAS and air density
TAS
= CAS/sqr(Rh/Ro) (Rh is function of height (see St. Atmosphere) and
follows from
measured static pressure and temperature,
Ro = 1.255 kg/m3 (value of Rh at msl))
GSpd = Groundspeed = TAS plus
windcomponent = Vgps
TEC, total pressure, static pressure and
temperature are measured quantities
IAS and CAS can be seen at option 15 of
the configuration page
TAS can be seen at address 204 of the test
page of the SR940 system
39.
What are the specific technical data
SR940 flight computer:
Battery voltage: 12 Volt nom. (11-15 Volt)
Current consumption: 110 mA (shortly appr. 1 A during pressure
valve activation)
Panel cutout of 80 mm diameter
Housing
BxHxL = 88x85x170mm + 42mm connector depth
Dot
matrix screen with excellent contrast (black on yellow/green)
This unit has been replaced by the ZS1
computer end of 2003.
SR940 second seat repeater:
Panel cutout of 80 mm diameter
Housing BxHxL = 88x85x60mm + 30mm
connector depth
Dot
matrix screen with excellent contrast (black on yellow/green)
This unit has been replaced by the ZS1
repeater end of 2003.
Analog indicator:
Current in micro amp range
Panel cutout of 61 mm diameter
Housing BxHxL = 67x67x50mm + 11mm connection pins
Unit has been replaced by a stepped needle
indicator (57mm or 61mm) with digital
output and is be available since
mid of 2003
GP941 GPS/Datarecorder:
GPS Engine: Garmin 12 channel receiver
Battery voltage: 12
Volt nom. (11-15 Volt)
Current consumption: 120 mA
Housing BxHxL = 73x30x110 mm (new design;
V=240 cm3)
Remark: The older GP940 unit is no
longer in production
Antenne:
Square shaped, 50x50 mm, height 8 mm,
active
5 Volt supply by GP941 unit via BNC
connector
NMEA output:
NMEA-0183 output is provided by the
SR940 9900 series flightcomputer as well as the
new GP941 GNSS recorder.
The $GPRMC line contains time,
coordinates, etc., according to the NMEA standard.
The $PZAN1 line provided by the
SR940 unit contains the “zeroed” altitude of either
the SR940 unit or the
GP941/GP940(v1.25) unit and the serial nr. of the SR940 unit.
The $PZAN1 line provided by the GP941 unit
contains the altitude of the GP941 unit
and the serial number of the GP941
unit.
The somewhat older GP940 unit does not
supply NMEA lines.
to
be continued (as always)
Reference:
ir.
K.P Termaat
Arnhem,
NL