Mitsubishi Electric 800 Series Instruction Manual page 357

 Block diagram of dancer control
Main speed command
*1
Dancer roll
setting point
Pr.133
PID set point
*1 The main speed can be selected in all operation modes, External (analog voltage input, multi-speed), PU (digital frequency setting) and
Communication.
 Outline of dancer control
• Dancer control is performed by setting "40 to 43" in Pr.128 PID action selection. The main speed command is the speed
command for each operation mode (External, PU, and communication). PID control is performed by the dancer roll position
detection signal, and the control result is added to the main speed command. For the main speed acceleration/deceleration
time, set the acceleration time to Pr.44 Second acceleration/deceleration time and the deceleration time to Pr.45
Second deceleration time.
NOTE
• Normally, set Pr.7 Acceleration time and Pr.8 Deceleration time to 0 s. When the Pr.7 and Pr.8 settings are large, dancer
control response becomes slow during acceleration/deceleration.
• If an automatic restart after instantaneous power failure is activated during dancer control, E.OC[] or E.OV[] is likely to occur.
In such case, disable the automatic restart after instantaneous power failure function (Pr.57 = "9999").
356
14.(A) Application Parameters
14.6 Dancer control
Acceleration/deceleration
PID deviation
PID control
+
1
Kp(1+ +Td S)
Ti S
-
PID feedback
Convert to 0 to 100%
Terminal 4
Output frequency PID adding value
Main speed
STF
of main speed
Ratio
Pr.128 = 42, 43
X14
Pr.128 = 40, 41
Potentiometer
ON
Target frequency
Acceleration/
Limit deceleration
+
+
M
Dancer roll position detection
Output frequency
Time