Mitsubishi Electric FR-A820-00046 Instruction Manual page 734

(A) Application parameters
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".
Fig. 5-275:
NOTES 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 page 5-524.)
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").
5 - 554
PID adding value
Main speed
STF
Signal overlay during dancer control
ON
Parameters
Output frequency
Time
I002707E