Delta MMC120 - Manual (Page 41)

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2. Select the printer and number of copies to print.
3. Click OK.
Plot Time
The plot time field controls the time interval between plot samples. Because the number
of samples for a full graph is fixed, the total graph length is also set by this parameter. In
a full graph, there are 1024 samples. The plot time units are 1000/1024 milliseconds.
Therefore, to request the graphs on an axis to be 4 seconds in length, this parameter
should be set to 4. This will result in 1024 samples, each 4000/1024 milliseconds apart,
for a total length of 4000 milliseconds.
The following two equations can be used for requesting a plot length:
Full Plot Length = PLOT TIME x 1 second
Plot Interval =
PLOT TIME x 1000 ms
1024
Special Status Values Available in Plots
TARGET SPEED
The target speed is displayed in a plot, both graphically and in the detail window, but it is
not displayed in the main status area. Like the ACTUAL SPEED , this parameter is
calculated. However, instead of being calculated off of TRANSDUCER COUNTS , it is
calculated from the TARGET POSITION . Therefore, when viewing a plot you can
compare the ACTUAL and TARGET SPEEDS to determine how well the actual move is
tracking the intended move.
Why is the TARGET SPEED Jagged During Constant Velocity?
With older versions of the firmware and monitor software, you may notice that during
some constant velocity moves, the TARGET SPEED is not flat. The jaggedness caused
by quantizing. That is, suppose that at constant velocity the axis is moving an average of
4.8 position units per millisecond. Because the motion controller only reads whole
numbers of position units, the TARGET POSITION would appear to increase by 4
position units for four milliseconds, and every fifth millisecond it would move 5 position
units. Therefore, if we were to calculate the speed based on a single interval, the speed
would just by 25% every fifth interval.
When the TARGET SPEED is calculated, smoothing is performed so that the speed does
not vary by 25%, but some jaggedness is left from rounded-off position units.
Raw Transducer Counts
The MDT Counts (lo) field holds bits 0-15 bits of the
TRANSDUCER COUNTS at the
given plot time period. The MDT Counts (hi) field is provided for use by technical