Mitsubishi Electric FR-A820-00046 (0.4K) Instruction Manual page 593

 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 (RS-485).
 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.
• The Pr.127 PID control automatic switchover frequency setting is enabled. The larger setting value between Pr.7 and
Pr.44 is used as the acceleration time during normal operation. For the deceleration time, the larger setting value between
Pr.8 and Pr.45 is used. (For the details of Pr.127, refer to
• 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").
592
5. PARAMETERS
5.14 (A) Application parameters
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
page 570.)
Target frequency
Acceleration/
Limit deceleration
+
+
M
Dancer roll position detection
Output frequency
Time