Lacerta M-Gen User Manual page 50

0 Inside the tolerance interval there will be no correction signal but
outside of it the device will try to correct the drifto to zero.
1 Inside the tolerance interval there will be no correction signal but
outside of it the device will try to correct the drift back to the
tolerance border only.
2 The same as mode 0 but this singals even inside the tolernace border
as a function of the current drift to remove low-frequency component
of the guiding curve (the drift's history).
This mode is more liable to cause oscillation, it may be compensated by
lowering the aggressivity or increasing the tolerance a little bit.
There is an "emergency" action for both axes. If the drift is beyond 3 times the tolerance
limit and is at least 1.0 (pixel), the averaging is turned off and correction signal is generated
immediately. This is for the case that the star is suddenly moved out of its position and is
needed to get it back to zero drift as fast as possible. Other causes can be wind, backlash and
mechanical errors in the mount. Currently this "emergency" behaviour is always active.
Handling DEC backlash:
If the DEC axis is not disabled, there is an option
This leads to the special backlash screen (shown right). There are two
ways offered to deal with backlash ('Dsbl.dir' and 'Compens.')

Dsbl.dir
: (switch) profile
"Disable direction". This method is the following. You setup the mount (depending on
the object's position) so that polar aligment is not correct and there is a slow drift in
DEC of the guidestar due to this. The mount has to follow the star in only one DEC
direction. With disabling the opposite direction's correction signal, the worm gear of
the DEC (or other source of the backlash) is always in contact and moves the telescope
like there was no backlash.
This switch has three states:
-
▲
▼

Compens.
: (switch) profile
Enables compensation of the DEC backlash time. The backlash time is the actual
correction's time of the mount without any movement, after You have reversed the
direction from a moving DEC. This time is constant while guiding and can be used
well only if the DEC backlash is predictably constant. For 'unpredictable' backlash
use lower compensation
backlash in DEC.
This switch (mode) has priority over the previous backlash-handling mode, if enabled,
Dsbl.dir
is interpreted and shown as disabled.
The following two items on the screen defines the backlash time value.
no disabling, both directions are enabled (normal guiding)
"up" is disabled (the direction when You press UP in manual mode)
"down" is disabled (...)
Time value so that it's not higher than the lowest expected
Backlash
.
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