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|User interface and configuration of the CT-2 controller is done
with the DrzTrack.exe program, a Windows program that you can
download. DrzTrack can also track the Moon and Sun.
See the download page for information on determining your firmware version and downloading this or earlier program versions.The rest of this page explains the use of the control and tracking program, DrzTrack.exe.
A new feature with DrzTrack V3 is the local control panel. This is a specially reduced in size dialog that can be used to easily control the azimuth only. It is designed for non EME usage, Tropo work, for example. Below are links to the various topics having to do with DrzTrack.exe.
|The DrzTrack program is
used to set up the various parameters that are needed by
the controller, to test and calibrate the encoders, and to track the
Moon and Sun. It may also be used to
relay tracking information from other tracking programs to the controller.
It does this by communicating with the controller via the
serial port. Configuration data for the controller is
selected by the user and saved in the controller's
non-volatile memory so that once the configuration is
done, it does not have to be redone unless a change is
When the DrzTrack program is started for the first time, it is necessary to set up the communications port and baud rate before it can communicate with the controller. Click on the "Program Setup" button and select the desired com port options. Click "OK" or "Apply" to save your settings. The program will remember your settings so you only have to do this once. The default rate that the CT-2 uses is 9600 baud. You can change this with the dip switches on the board, see Switch configuration and Setting for more details.
Once the Comm port and baud rate are set, DrzTrack will start communicating with the controller. The status message (in bold print near the top) will change from "No Connection to Controller" to "Controller Responding to Commands", and the communications LED indicator will begin to flash. At this point no movement commands will be sent to the controller but it will try to display the current position and status of the controller board. Some of the status and communications indications will be operative as shown below, but they may not all work as the encoders have not yet been set up. Note that it is necessary for communication with the controller board to be working before the encoders can be configured. On a new controller, the default setting for encoder type is A/D for both Azimuth and Elevation. So if you are connected to some different kind of encoders, no position information can be displayed until you set up the encoders. However the little 'LED' next to the Reset button should be flashing at a rapid rate, indicating that serial communication with the controller has been established.
Once communication is working, click on the "Encoder Configuration" button. The following window will appear:
Below is a screen shot of what the control program window looks like when in this mode:
This screen shot shows DrzTrack version 3.15, but it is the same for the newest 3.19 version.
Note that the two compasses are showing Antenna Position and degree readouts, and the Movement enabled status 'LED' is on. Also, the 'LED' beside the reset button is flashing on and off.
A new feature for version 3.15 `is the band select drop down box near the bottom right. You can select what band you want to operate so that the correct settings for that band are used. In particular tracking offsets for each band can be set in the program setup dialog, tracking tab.
|In the Controller Status section of the window there
are 10 indicators that show controller status. You can
think of these indicators as LED's (Light Emitting
Diodes) that might be used to show status on a hardware
board. For the remainder of this document I will refer to
them as LED's.
Eight of the LED's are used to show Antenna Motion status. Four are for motion requests. These will be lit when the controller board has received a request to move the antenna but it has not yet initiated actual motion. This can happen in two circumstances:
a) The antenna has just stopped moving and the controller's stop timer has not yet expired. As soon as the timer times out the controller will start moving the antenna and the status LED will change from Requested to Current.
b) The controller has detected an error and has disabled movement. In this case the "Movement Enabled" LED will be off. This will happen only if the controller detects that the antennas are not moving when they should be. If no motion is detected after the Move Timeout period selected for the encoder, the controller board will stop all movement and disable further movement. It is necessary to reset the controller before motion can be re-enabled. This can be done with the "Reset Controller" button, or by power cycling the controller board.
The final LED is a communication indicator. When the program is communicating with the controller it will flash on and off.
|For any encoder type it is necessary to calibrate the controller to
the actual antenna position in order to get accurate readings. This is
done with the two calibrate buttons on the bottom of the window
(Calibrate AZ and Calibrate EL). The elevation and azimuth calibrate
dialogs are nearly identical, so only the elevation dialog is shown.
However the incremental encoders require different settings so they have
their own, different dialog. The dialog shown below is for A/D
elevation, and will be the same for all others except the incremental
|Absolute encoders have some special calibration considerations.
Absolute encoders output an absolute position count from zero to 360
degrees, for one turn of the encoder shaft. To calibrate them it
is only necessary to do a "Min Set", which sets the zero position.
It is not necessary
to do a max set and the "Max Set" button is disabled for absolute encoders
(however see the section below about scaling absolute encoders)..
Another consideration is for the elevation encoder. If you use the inclinometer then 90 degrees is represented by just one quarter of the 360 degrees, thus you must set the calibration range as zero to 360. You could also use other end points as long as the total range remains at 360 degrees. For instance you could use -10 to 350 degrees. That would allow you to move the antenna to -10 degrees and still have correct readout.
If you use a shaft encoder for elevation, you could set the calibrate min and max to zero and 90, and then the encoder will show that range in a single turn of the encoder shaft (output is divided by four). Normally setting the calibrate range as 0-90 is better because the resolution will be 4 times better, but there is one side effect. When your antenna reaches 90 degrees, the display will 'wrap' back to zero. This can be disconcerting if you are not expecting it. Also, when absolute encoders go backwards past the zero position, the display will 'wrap' back to the maximum range setting (90 or 360). It is possible to change the range for absolute elevation encoders to other than 0-90 or 0-360. For instance you could set it to -10 to 350. This would still produce the full 360 degree range in a single turn, but the end points are different. This can be useful for antennas that can go below zero for testing or ground noise measurements.
It is also possible to use a range that is not 90 or 360 degrees. For example suppose you set it for a range of 0-180. This will produce the 180 degree count a single turn and then wrap back to zero. Or a range of -15 to 90 would mean that the range of 105 degrees would be produced for a single turn of the shaft. Of course to use these alternate settings one has to have the gearing of the shaft adjusted accordingly.
Also, for absolute encoders it is not necessary to move the antenna to the "Calibration Min" position. You may use the "Set Current" button to properly calibrate the antenna at any known position. In this case the encoder itself is recalibrated to the new position, so the min and max points will remain the same.
Absolute encoders can also be reprogrammed to change their address, direction, and resolution. Full information on reprogramming and usage of these parameters is shown on the Detailed Configuration page.
|The section above details how absolute encoders are normally set up,
but there can be situations where the ability to scale the output of the
encoder over a degree range is desired. For instance if the
gearing between the antenna and the encoder is not 1:1 then the output
of the encoder will get further from correct the more it is turned away
from the zero position. To allow scaling, there is a check box in
the setup menu called "Allow Scaled Absolute AZ". When this box is
checked then the "Set Max" button in the calibrate dialog will be
enabled for an absolute encoder in the Azimuth position. This then
allows you to turn the antenna to the true end position and then click
"Set Max". Now the antenna will track correctly.
If the encoder to antenna gearing is less than 1:1 this works with no problem, however if the gearing were more than 1:1 there is a problem. This is because absolute encoders 'wrap' their value at the end points. So if Set Max is done when the encoder is at a position greater than 360 degrees, the value returned would be very low and the scaling would fail. So Scaling of absolute encoder output values only works correctly when the gearing is less than 1:1.
Additionally, scaling only works when the absolute encoder is in the
azimuth position. For elevation, use an absolute inclinometer and
no gearing (or scaling) is necessary.
|Incremental encoders are enough different than others so somewhat
different calibration routines are needed. Incremental encoders emit
pulses in a quadrature format that are used by the controller for
counting and for directional information. Full calibration always
requires that the min position be set first, so in the dialog shown
below, the 'Set Max' button is disabled until after a 'Set Min' has been
done (see the calibrate description above for more details on how 'Set
Min' and 'Set Max' work. Also the 'Enter Current Position' field
and the 'Set Current' button are disabled unless 'Adjust' or 'Z Reset'
is selected at the top.
'Enter Current position' works much the same as for the other encoders, see above.
After calibrating the antenna with Z-Indexes, and whenever entering the incremental calibrate dialog when a Z-Index calibration has already been done, a second dialog box will be shown along side of the calibrate dialog shown above. This box shows the results of the Z-Index counting and is shown to the left.
Note the Range at the bottom that is shown both in degrees and count. This is how close to the actual position your antenna must be in order to get an accurate Z-Reset operation. If the antenna position error is greater than this amount then the wrong Z-Index will be used and the calibration will be off by one or more rotations of the encoder.
Remember, this is all automatic and each time a Z-Pulse is detected the controller will adjust it's calibration if necessary. Thus any minor errors that might creep into the count are automatically accounted for. The greater the gearing (up to 16:1), the more often the calibration will be checked and adjusted. However with higher gearing, the amount of antenna error that can be tolerated when making a Z-Index adjust is reduced.
|For EME operation, it is often desirable to be able to point the antenna below the horizon. If your antenna mount can do this you may configure the controller and control program as follows. Assume your antenna has a range of -15º to 90º. Set the encoder calibration range to be -15 to 90º and do a normal calibration of the antenna*, setting the antenna to -15 degrees for 'Min Set'. Now, when you move the antenna below zero, the LCD display on the controller and the DrzTrack program will indicate the negative degrees. (*However for absolute encoders the range should be set to -15 to 345 for one to one gearing. See the absolute encoder calibration paragraph, above.)|
|You may initiate manual movement of the
antenna whenever desired. If the controller is in tracking mode, that
mode will be ended and manual control will start. There are
several ways to move the antenna manually.
1. By entering the desired position in degrees into the fields below the azimuth or elevation compasses. If you want to move elevation and azimuth both at the same time, enter both values and click the "go to EL/AZ" button. If you only want to move in one plane then use the "Go to EL" or "Go to AZ" buttons. When these buttons are clicked, they will stay down and the button text will change to the word "Stop". The button will stay down until the target position is reached. If you want to stop antenna movement before the target is reached, click the same button (which is now labeled "Stop").
2. If you place the mouse cursor over one of the compasses and place it at the position you wish to move to and then left-click the mouse the position selected will be loaded into the position field below the compass. Then you may click the appropriate GO button below. However if the box "Move on Click" is checked then the antennas will move as soon as the new position is clicked with the mouse. You can still stop motion at any time by use of the "stop" button.
In all of the methods above, a request to move to the position entered or clicked is sent to the controller and the position and status will continue to be monitored while it is moving. It will continue moving until it reaches the selected position, or until it reaches one of the limits set in the configuration dialog. However the movement timer will still time out and stop the motion motors if the antenna fails to move. Also the stop timers will work. For an example of this, suppose you have the stop timer set for the default value of 5 seconds. If you are moving up and you change immediately to down, the antenna will stop for 5 seconds before reversing direction. During the time it is stopped, the request Down LED will be lit but the current Down LED will be off.
|Once the controller has been set up, calibrated, and
tested, you can begin tracking. For the Moon or Sun, the DrzTrack
program provides excellent tracking as well as clock, astronomical
data, transmission timing, and DX station parameters. See the
with Other Programs page for details on using other tracking
programs with DrzTrack and the CT-2 controller.
DrzTrack directly controls the CT-2 board to provide tracking of Moon and Sun. There are two ways that other programs may interact with the CT-2 controller board. One is via direct serial communication from the tracking program to the controller. The F1EHN, MoonSked, and EME2008 programs use only the serial mode. Nova and TrakSM can use serial mode when they are set for the NovaComm or EasyComm modes. Nova and TrakSM may also be used in the DDE mode, and SatScape can only be used in DDE mode.
DDE stands for "Dynamic Data Exchange", and is a method for multiple programs running on the same computer to communicate with each other. A tracking program that uses DDE is said to be a DDE server and it sends tracking information to another program via DDE. The DrzTrack program is a DDE client and can receive this tracking information and then relay it to the CT-2 controller board via the serial port interface. When DrzTrack is functioning in this manner, the Tracking section of it's screen will show the name of the body or satellite being tracked, and the current position of that body as determined by the DDE messages from the tracking program. In this mode, the actual tracking program (Nova, SatScape or TrakSM) may be minimized on your computer screen and the DrzTrack screen will show both the current satellite position and current antenna position.
When DDE tracking is started. tracking will be paused, requiring you to click the pause/resume button to start moving the antenna. This is a safety feature so the antenna does not start moving until you can see it happening on the DrzTrack screen
If you are using a tracking program that directly communicates with the CT-2 controller via the serial port, you must set up DrzTrack to use that program. Then the program can be run right from DrzTrack. When you end the tracking program you will automatically return to the DrzTrack program where you can test or reset calibration if necessary. This saves a lot of switching back and forth between programs. When running one of the DDE trackers it is necessary to run it from DrzTrack so that both are operational at once.
The title section of the tracking box in the main DrzTrack shows the name of the tracking program being used. Initially this will always be DrzTrack itself, you must specify any other tracking programs you wish to use and where they are located on your computer, and what the interface method is.
This is done from the "Program Setup" dialog, in the Programs tab. Here you will see a list of all programs that you have already set up.
You can add a new tracking program by clicking the "New Program" button, or click any existing program in the list to change it's setup parameters or remove it from the list.
|Moon or Sun tracking can be done with the DrzTrack program that
comes with the CT-2 controller (see download page).
Before starting tracking it is necessary to configure the DrzTrack
tracking parameters shown below. This dialog is accessed by
clicking the "Program Setup" button.
Enter your call sign and six digit grid square and select the band you will be operating on. The band selection causes the program to use the setup that you have configured for each band, including T/R sequence and any aiming offset you may need for the selected band. Band is also used to properly calculate Doppler shift and sky temperature for the astronomical data display. Select whether you wish to track the Moon or the Sun, and select your mount type (usually Az/El). For schedules, DrzTrack contains a handy sequence clock that shows transmit periods in red and receive periods in blue. Click the "Edit Band Data" button to set the sequence and any offsets for the selected band.
When you are done, click OK to exit setup. (Note that data entered in any screen while in setup will not be saved unless you exit setup with the OK button.)
The final tab in the setup dialog is for configuration of Absolute encoders. It can only be used if an absolute encoder is present and working.
High resolution may be used if you require better than .1 degree position sense accuracy.
Unlike the other setup tabs, on this one the values are sent to the
encoder as soon as you click the 'Set' button, making it unnecessary to
use the OK button when exiting from setup.
Note that the title of the tracking box shows what program you are currently tracking with. Whenever an alternate tracking program has not been started, the title will be "Tracking with DrzTrack". If you use the Run button to start an alternate program that communicates with DrzTrack via DDE, then the title will change to show that program.
Just below the title is a status message that shows the current condition of the tracker. The status message shows the body being tracked and shows it as 'paused'. The current Moon or Sun position will also show in the position boxes on the left. Clicking the button marked "Resume Tracking" will start the process of following the Moon or Sun with your antenna. The button label will change to "Pause Tracking" and if you click it again tracking will be paused. Note that your correct six digit grid square must be entered in the setup dialog in order for the program to calculate correct Moon or Sun positions.
This window may be moved independently of the main DrzTrack window to any convenient place on your screen. To remove it, click the red X at the top right.
Note that DrzTrack uses two files to obtain DX station location and Sky temperature. These files are Tsky.dat and Call3.txt and they must be in the same folder as DrzTrack.exe.
I want to give credit here to Joe Taylor, K1JT as the original developer of the sun and moon position algorithms.
The Moon azimuth and elevation are shown for any DX station of grid that was entered in the Dx Station field on the main dialog, as shown below. Pressing the Enter key immediately after entering the call or grid will automatically bring up this Moon and Sun Data screen.
The DX station's call sign may be entered on the main dialog as shown here. If the lookup by call fails or returns the wrong location, you may enter the grid, if known.
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