Hitachi SJ7002 Series Instruction Manual page 98

3–14
"A" Group: Standard Functions
Func. Name/
Code Description
A038 Jog frequency setting
Defines limited speed for jog
A039 Jog stop mode
Defines how end of jog stops
the motor
Torque Control
Algorithms
Keypad
SRW OPE
0.5 to 9.99 (Hz)
00
FRS Free-run stop, jogging disabled during
motor run
0 1
DEC Controlled deceleration, jogging
disabled during motor run
02
DB DC braking to stop, jogging disabled
during motor run
03
R-FRS Free-run stop, jogging always enabled
04
R-DEC Controlled deceleration, jogging always
enabled
05
R-DB DC braking to stop, jogging always
enabled
The inverter generates the motor output
according to the V/f algorithm or the
sensorless vector control algorithm. Param-
eter A044 selects the inverter torque control
algorithm for generating the frequency
output, as shown in the diagram to the right
(A244 and A344 for 2nd and 3rd motors,
respectively). The factory default is 00
(constant torque V/f control).
Review the following descriptions to help
you choose the best torque control
algorithm for your application.
• The built-in V/f curves are oriented
toward developing constant torque or
variable torque characteristics (see
graphs below).
• The free-setting curve provides an even
more flexible characteristic, but it
requires more parameter settings.
• Sensorless vector control calculates an
ideal torque vector based on current
motor position, winding currents, and so
on. It is a more robust control method than the V/f control methods. However, it is more
dependent on actual motor parameters and will require you to set these values carefully or to
perform the auto-tuning procedure (see
obtain optimum performance.
• Sensorless vector control, 0Hz domain increases the low-speed torque performance (0–
2.5Hz) via an advanced Hitachi torque control algorithm. However, you will need to size the
inverter for one frame size larger than the motor for proper operation.
• Vector control with sensor requires expansion card SJ–FB encoder feedback board and a
motor shaft encoder. Choose this method when precise position/velocity control is required.
Range and Settings
Inverter Torque Control Algorithms
V/f control,
constant torque
V/f control,
variable torque
V/f control, free-
setting curve
Sensorless vector
(SLV) control
Sensorless vector,
0Hz domain
Vector control with
sensor
"Auto-tuning of Motor Constants" on page
Defaults
Run
Mode
FEF2 FUF2 FF2
Edit
FE2 FU2 F2
Lo Hi
(EU) (USA) (Jpn)
✔ ✔
1.00 1.00 1.00
✘ ✔
00 00 00
A044
00
01
02
Output
03
04
05
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