CT34002a_e.doc / Nov-15
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8.4.
Setting of the Proportional Gain
The register “Gain Correction” determines how strong the controller responds to position and
speed errors of the drive. In principle, this setting therefore should be as high as possible.
However, depending on dynamics and inertia of the whole system, too high gain values will
produce stability problems.
Please try to increase the setting of Correction Gain from 0.500 to 1.000, 1500, 2.000, 2.500,
3.000 etc. However, as soon as you find unsteady operation, noise or oscillation, you must
reduce the setting again correspondingly.
We also recommend to ramp up and down the master while checking the color bar and the
differential counter for stable operation.
Actual value no. 6 displays the distance between the cutting pulses (see chapter
7.3). Thereby you can check the proper operation of the cutting pulse.
Once you have successfully concluded these steps, you can exit the Adjust menu.
Now your machine is ready for operation and you can run initial test cuts without material (see
next chapter).
8.5.
Tuning the controller
Start a homing sequence by activating input “Homing”. The cutting roll performs a homing
sequence and moves to the home position, which is located opposite to the centre of the
synchronous zone.
For the very first trials you should use a long length setting (“Cutting Length”) and a slow
line speed.
Start the line drive or move the measuring wheel at the line encoder to simulate the
moving material.
Set “Immediate Cut” command and see how the controller executes a first cutting cycle.
Set the “Start” command. The cutting roll will wait for expiration of the length and then
continuously execute cutting cycles.
By actual value no. 7 you can display and check the actual cutting length (see chapter
7.3).
Observe the position error at the differential counter or the bar graph display. During the
whole cycle the position error should not exceed values like 30 and the bar graph should
remain in the centre area all the time. Increase the line speed step by step and continue
the observations.
When you have achieved settings to keep the bar graph at the centre position at all line speeds
and with all cutting length presets, there is nothing to improve.
