46
6250 Servo Controller User Guide
Scaling
The scaling commands allow you to scale acceleration, deceleration, velocity, and position to
values that are appropriate for the application. The
SCALE
,
SCLA
,
SCLV
,
SCLD
,
PSCLA
,
and
PSCLV
commands are used to implement the scaling features. Note that scaling only
applies to encoder values. If using ANI feedback (6250-ANI only), scaling does not apply.
NOTE
To maximize the efficiency of the 6250's microprocessor, the scaling multiplications are
performed when the program is defined or downloaded. Therefore, you must enable scaling
(
SCALE
) and define the scaling factors (
SCLD
,
SCLA
,
SCLV
,
PSCLA
,
PSCLV
) prior to defining
(
DEF
), uploading (
TPROG
), or running (
RUN
) the program. This can be accomplished by
defining all scaling factors via a terminal emulator just before defining or downloading the
program; you should also put the scaling factors into the startup (
STARTP
) program.
Default: Scaling is
Disabled
The default condition of the 6250 is with scaling disabled (
SCALEØ
):
❏
All programmed acceleration and deceleration values are entered in encoder revs/sec
2
; these
values are internally multiplied by the encoder resolution (
ERES
) value to obtain acceleration
and deceleration values in encoder steps/sec
2
for the motion trajectory calculations.
❏
All programmed velocity values are entered in encoder revs/sec; these values are internally
multiplied by the encoder resolution (
ERES
) value to obtain velocity values in encoder
steps/sec for the motion trajectory calculations.
❏
All distance (
D
and
PSET
) values are entered in encoder steps; these values are internally
represented as encoder steps.
Acceleration & Deceleration Scaling (
SCLA
/
PSCLA
)
If scaling is enabled (
SCALE1
), all accel/decel values entered are internally multiplied by the
acceleration scaling factor (
SCLA
) to convert user units/sec
2
to encoder steps/sec
2
. Acceleration
scaling affects the following commands:
A
,
AA
,
AD
,
ADA
,
HOMAD
,
HOMADA
,
JOGA
,
JOGAA
,
JOGAD
,
JOGADA
,
JOYA
,
JOYAA
,
JOYAD
,
JOYADA
,
LHAD
,
LHADA
,
LSAD
, and
LSADA
.
Path Scaling: If you are using the 6250's linear interpolation feature, the
PA
,
PAA
,
PAD
and
PADA
commands are affected by the path acceleration scaling factor (
PSCLA
).
As the acceleration scaling factor (
SCLA
/
PSCLA
) changes, the accel/decel command's range
and its decimal places also change (see table below). An acceleration value with greater
resolution than allowed will be truncated. For example, if scaling is set to
SCLA1Ø
, the
A9.9999
command would be truncated to
A9.9
.
SCLA
/
PSCLA
Value
Decimal Places
Max. Accel/Decel
Min. Accel/Decel (resolution)
1 - 9
10 - 99
100 - 999
1000 - 9999
10000 - 99999
100000 - 999999
0
1
2
3
4
5
999.9999 x
ERES
SCLA
0.001 x
ERES
SCLA
Velocity Scaling (
SCLV
/
PSCLV
)
If scaling is enabled (
SCALE1
), all velocity values entered are internally multiplied by the
velocity scaling factor (
SCLV
) to convert user units/sec to encoder steps/sec. Velocity scaling
affects the following commands:
V
,
HOMV
,
HOMVF
,
JOGVH
,
JOGVL
,
JOYVH
, and
JOYVL
.
Path Scaling: If you are using the 6250's linear interpolation feature, the
PV
command is
affected by the path velocity scaling factor (
PSCLV
).
