This tool allows you to assess the Dec backlash characteristics of your mount.
It works by turning off RA tracking and making a series of alternating North and South moves. This produces a zigzag pattern like shown in this snapshot:
The controls are very simple:
N/S Move Duration (Secs): Controls the duration of each discrete North and South move. The moves will occur at the mount's current guide rate.
| NOTE: Most mounts do not do well with a very short duration, so if you see an irregular sawtooth pattern you might want to try increasing the duration. 5 seconds is typically a good minimum duration. |
Image Duration (Secs): Controls the duration of the entire image.
Dec Movement Method: Sets the movement method: ASCOM Dec -RA, ASCOM Dec +RA , RELAY X, or RELAY Y. Of the two relays, RELAY Y usually moves the declination axis. DEC -RA first stops RA tracking then issues Dec moves while tracking is stopped. However, some mounts won't accept DEC moves while tracking is stopped so DEC +RA starts an RA move and simultaneously issues Dec moves. This method only works if the mount can do asynchronous ASCOM PulseGuide commands (many mounts can't do this).
Extra Delay Between Moves (msec): This inserts an extra delay after the completion of a move. This may be needed with some telescopes because they might ignore the new move command because the old move has not completed. You should experiment with this setting if the star pattern does not look like a sawtooth.
Before the Start button is enabled you must connect to the scope and camera on the Setup tab of the PEC page.
You can enable the Magnifier by clicking the Enable checkbox. Then as you move the mouse over any part of the image it will be magnified in the small box in one of the corners. The box can be placed at any of the four corners by changing the setting of the Position combo box. You can use the Magnifier to closely examine the declination direction transitions.
