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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 track the Moon and
Sun. It can interface with some other programs to track other
This is the DrzTrack version 5.12 main dialog.
Note that most of the buttons (from previous versions) have been moved to menu items at the top in the Setup, Configuration, or Calibrate menus.
The message box shows 'Responding to Commands'. This message is shown when DrzTrack is connected to the controller via the RS-232 serial link. Also, the 'Activity Indicator' button is flashing on and off.
The two compasses are showing Antenna Position and degree readouts. There are two fields at the top that show the current Moon or Sun position, depending on which one is selected in the setup dialog.
At top right there is a band selector. It is used to select the current band of operation. This allows things like correct Doppler shift, antenna offsets, and operating sequences, for each band, to be shown in the main window and elsewhere. Bands are set up in the Setup menu.
At top middle is the Tracking button. When clicked it stays down and the text changes to 'Stop Tracking', indicating that tracking is in progress.
Under the compasses there are two sets of buttons and fields. They can be shown or removed via checkboxes in the setup dialog. Here they are both shown. First there are the two Offset buttons. They can be used to set a quick tracking offset if needed, See Band Offsets in the detailed settings page.
The Go buttons and fields allow you to enter a position in degrees, and then clock a 'Go' button to tell the controller to move the antenna to the entered position. These buttons are not active when tracking.
At the right there is a field named 'Dx Station Call or Grid'. Entering valid information in this field and pressing enter brings up an auxiliary window called 'Moon and Sun Data'. It will show Moon and Sun positions for your station and for the selected DX station or grid square, as well as other astronomical data.
Also at right is a field labeled 'Polarity' that can be used to show antenna polarity if a 0-5 volt DC polarity indicator voltage is connected to the controller. This is enabled and set up via the Setup menu.
At the bottom are the Reset, Local Control Panel, and Exit buttons. The reset button causes the controller to reboot. The local control panel can be used when only controlling azimuth (for non EME operation). Many more details about the main window and other windows and operational controls are described below and in the Detailed Settings page.
|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 the 'Setup' menu item in the main dialog. Then select the "General" tab and then 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 Communications 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 activity 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 above, 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 black dot (activity indicator) should be flashing, indicating that serial communication with the controller has been established.
Once communication is working, open the configuration menu at the top of the screen and select the Encoders menu item. The following window will appear:
|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 calibrate menu at the top of the window. Select the
Azimuth or the Elevation menu item. 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 use 1:1 gearing and set the calibrate min and max to zero and 90. Then the encoder will produce the same output as an absolute inclinometer, giving 0 to 90 degrees in 1/4 turn. It is not necessary or desirable to gear up absolute encoders to get more resolution. You can set the encoder to "high resolution" mode and get .01 degree accuracy. (In low resolution mode the accuracy is .1 (1/10) degree.) See the section about Absolute Encoder programming in the Detailed Settings page.
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 (0 to 360 degrees).
Absolute encoders can also be reprogrammed to change their address, direction, and resolution. If an absolute encoder has been selected then an additional button will be displayed in the corresponding calibration window, entitled "Absolute Encoder Programming". Full information on absolute encoder programming is shown on the Detailed Settings 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 absolute encoder calibration dialog called "Enable Scaled Absolute"
(*). 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.
* For DrzTrack versions prior to 5.10 the scaled absolute check box is located in the 'General' tab of the setup dialog.
|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.)|
|On the main window, at the top right corner of each antenna position compass there is a
square black box. This box shows the movement condition of the
antenna for each direction. When the box is black the antenna is
stopped and no movement has been requested, When motion has been
requested the box will turn yellow for a short time and then green.
Yellow indicates that movement has been requested but has not yet
started. Green indicates that the motor for that direction has
been turned on and the antenna should be moving. In addition to
the color display, the boxes will also contain an arrow that shows the
direction that the antenna is moving, or has been requested to move.
For elevation the arrow will point up or down. For azimuth the
arrow will point to the left for clockwise motion, and to the right for
counter clockwise (think of the arrows showing the direction it will
move when starting at 180 degrees).
The yellow request indication happens when the antenna has just stopped moving and then another motion request is received. When motion is stopped, the controller starts a stop timer for the length of time that is set in the encoder configuration window. The Indicator will remain yellow (and the antenna will not move) until the stop timer expires. As soon as the timer expires the controller will start moving the antenna and the motion box will change from yellow to green.
The motion indicator may also be yellow when controller has detected an error and has disabled movement. When this happens an error message will be displayed on the screen and the message section of the window will show "Movement Disabled". 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 to re-enable movement. This can be done with the "Reset Controller" button, or by power cycling the controller board.
|You may initiate manual movement of the
antenna when the controller is not in tracking mode. 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, and click the 'Go' button next to the field. You may move elevation and azimuth both at the same time, enter both values and click both 'Go' 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. By default, you can also use the mouse to select the manual move
end point. This feature can be disabled with the 'Disable Move on
Click' box in the Program Options setup window (see the
section of the detailed settings page).
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 tracking limits set in the configuration window. 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 elevation motion indicator will be yellow and the elevation motor will not yet be started.
|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 in the Detailed Settings page for details on using other tracking
programs with DrzTrack and the CT-2 controller. For tracking
with DrzTrack, you must first set up your station parameters and band
settings as described below.
To access the setup windows click the Setup menu item in the main dialog. There are 5 sections in the setup dialog. The Tracking and the Band settings are described here. The General, Programs, Position Offsets and Boot Load descriptions are in the Detailed Settings page.
Enter your call sign and six digit grid square and select whether you wish to track the Moon or the Sun, and select your mount type (usually AZ/EL).
Entering the correct six digit grid square is essential so that the Moon or Sun position will be accurately shown for your location.
Below is the tracking portion of the main DrzTrack dialog window. Note that the run button shows 'Run Nova', because Nova is the alternate program selected in the setup screen (program setup tab).
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.
The current Moon or Sun position is shown in the position boxes on the left. 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 position.
The tracking control button is at center. When not tracking it will be labeled 'Start Tracking'. Clicking the 'Start Tracking' button will start the process of following the Moon or Sun with your antenna. The button will stay in the down position and the label will change to 'Stop Tracking'. If you click it again tracking will be stopped.
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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