Danfoss MCO 305 Design Manual page 97

MCO 305 Design Guide
__ APOSS Tools __
Master and Slave Marker Positions
Enter the master position (or the slave position in
the case of slave synchronization with marker) for
which the marker has been set. For example, the
beginning of the box in the illustration below is the
master marker position.
The position of the curve where the marker is detected is calculated from the master marker position and the
marker distance. This allows you to fix the correction area.
If → Master Marker is enabled, then a vertical green line will indicate the master marker position in the curve
profile diagram. If → Slave Marker is enabled, then a horizontal green line will indicate the slave marker
position.
Interpolation and Number of Intervals
Controllers containing firmware older than MCO 5.00, require "interpolation points" when processing curve
profiles. For newer controllers, these are no longer necessary and this topic can be skipped entirely. The
firmware version of the controller is displayed in the APOSS Communication Window when the controller is
first connected in the APOSS-IDE.
If the curve profile is intended for an older controller, then the Interpolation enabled checkbox should be
selected. This can be done either when a new curve profile is added or by using the "Set" button. It cannot
be done directly from the Curve Data index card.
Older controllers require many more Fix points than newer controllers. If interpolation is enabled, then the
CAM-Editor will do this automatically for the user by adding interpolation points (i.e. "virtual" Fix points) on
a uniformly spaced "interpolation grid". The size of the interpolation interval (i.e. the distance between
interpolation points) determines the accuracy with which the controller can follow the curve profile and must
be chosen by the user based on the accuracy requirements of the application. Smaller interpolation intervals
will give higher accuracy but will result in more interpolation points and larger arrays in the controller. Very
small intervals can also cause the controller to have performance problems as a result of the large number
of short segments. The "Interval Time" (found on the Curve Info index card) should not be smaller than 20-
30 ms.
In order to avoid a fractional number of interpolation points, the Master Length is required to be an integral
multiple of the interpolation interval. To ensure this, the CAM-Editor will always snap the last Fix point to the
interpolation grid. When the "Set" button is used, the CAM-Editor will also ensure that the new Master
Length is a multiple of the interpolation interval. As well, when the Master Length is changed with the "Set"
button, the number of interpolation points is changed automatically so that the interpolation interval (i.e.
the curve accuracy) remains unchanged. It is recommended that the master cycle length be at least 1000 in
order to allow for an adequate resolution of the interpolation grid.
Although not strictly necessary, it is recommended that user Fix points also be placed exactly on the inter-
polation grid. The Snap all to grid toolbar button and the Snap on Grid checkbox option can be used to
assist the user in placing Fix points on the interpolation grid. If Fix points are not placed on the interpolation
grid, then the actual curve profile followed by the controller will pass near the off-grid Fix points but may
not pass exactly through them.
97
®
MG.33.L5.02 – VLT is a registered Danfoss trademark