User guide

Chapter 3. Basic Operation Setup 85
SCLV/PSCLV Value
(steps/unit)
Velocity Resolution
(units/sec)
Decimal Places
1 - 9
10 - 99
100 - 999
1000 - 9999
10000 - 99999
100000 - 999999
1
0.1
0.01
0.001
0.0001
0.00001
0
1
2
3
4
5
Use the following equations to determine the maximum velocity range for your product type.
Max. Velocity for Stepper Products Max. Velocity for Servo Products
8,000, 000
n




SCLV
n = PULSE x 16; If n < 5,
then n is set equal to 5.
If n > 5, then all fractional
parts of n are truncated.
Encoder or Resolver Feedback:
1000 x ERES
SCLV
LDT Feedback:
1000 x LDTRES
SCLV
ANI Feedback:
1000 x 819
SCLV
Distance Scaling (SCLD and PSCLD)
FOLLOWING:
The master axis can
be scaled with the
SCLMAS command,
and the slave axis
can be scaled with
the SCLD command.
Refer to page 196 for
details.
Steppers: If scaling is enabled (SCALE1), all distance values entered are internally
multiplied by the distance scaling factor. Since the SCLD/PSCLD units are in
terms of steps/unit, all distances will thus be internally represented in motor
steps (if in ENCØ mode) or encoder steps (if in ENC1 mode).
Servos: If scaling is enabled (SCALE1), all distance values entered are internally
multiplied by the distance scaling factor. Since the SCLD/PSCLD units are in
terms of counts/unit, all distances will thus be internally represented in encoder,
resolver, LDT, or ANI counts.
All distance commands for non-interpolated motion (e.g., D, PSET, REG, SMPER) are
multiplied by the SCLD command value. Distance commands for linear and circular interpolated
motion (e.g., PARCM, PARCOM, PARCOP, PARCP, PLC, PLIN, PRTOL, PWC) are multiplied
by the PSCLD command value.
LDT Users—Programming In Inches Or Millimeters
The default SCLD value is 432 (SCLD432,432), which allows LDT users to program in inches.
To program in millimeters, use a SCLD value of 17 (SCLD17,17). These factors must be
multiplied by the number of recirculations if the LDT uses more than one recirculation.
As the SCLD/PSCLD scaling factor changes, the distance command's range and its decimal
places also change (see table below). A distance value with greater resolution than allowed will
be truncated. For example, if scaling is set to SCLD4ØØØ, the D1Ø5.2776 command would
be truncated to D1Ø5.277.
SCLD/PSCLD Value
(steps/unit)
Distance Resolution
(units)
Distance Range *
(units)
Decimal
Places
1 - 9 1.0 0 - ±999999999 0
10 - 99 0.10 0.0 - ±99999999.9 1
100 - 999 0.010 0.00 - ±9999999.99 2
1000 - 9999 0.0010 0.000 - ±999999.999 3
10000 - 99999 0.00010 0.0000 - ±99999.9999 4
100000 - 999999 0.00001 0.00000 - ±9999.99999 5
* 6270: In the table below, shift the decimal place in the “distance range” column one place to the left.
NOTE FRACTIONAL STEP TRUNCATION NOTE
If you are operating in the incremental mode (MAØ), when the distance scaling factor (SCLD or
PSCLD) and the distance value are multiplied, a fraction of one step may be left over. This
fraction is truncated when the distance value is used in the move algorithm. This truncation
error can accumulate over a period of time, when performing incremental moves
continuously in the same direction. To eliminate this truncation problem, set SCLD or PSCLD
to 1, or a multiple of 10.