Toshiba Tosvert Inverter E6580772 - Manual (Page 22)

E6580772
21
3.2.5 Monitoring method for feedback amount
Motor rotation speed can be monitored.
The motor is equipped with status monitor which is displayed on the panel and analog monitor which used
analog output terminals (FM, AM terminals)
Set items① and② for motor speed monitoring.
① Speed feedback (real-time value) (Unit: Hz/free unit)
The real-time display of motor speed can be made (Monitor display setting: 6).
② Speed feedback (one-second filter) (Unit: Hz/free unit)
The filtered motor speed (feedback value) is displayed. (Monitor display setting: 7).
The monitoring for the above① and② is possible also in cases except for pt =8 (PG feedback vector control
operation). For example, the monitoring can be used for confirmation of the initial PG feedback amount in open
loop (V/F operation and the like).
In order to monitor motor rotation speed in condition monitoring, it is necessary to change the setting for
extended parameters (f711 to f714).
Refer to
In order to monitor motor rotation speed by the analog output terminal, it is necessary to change the setting
for basic parameter (fmsl fm ) and extended parameter (f670 f671 .
Refer to (Meter Setting and Calibration) section of the inverter manual.
3.2.6 Accuracy of speed control
The accuracy of speed control with the PG feedback can be obtained by the following formulae.
Accuracy of speed control = Command frequency accuracy + feedback detection accuracy
Command frequency accuracy
0.01(Hz)
F (Hz)
c
100
1
2
(using digital command)
Feedback detection accuracy
1
2 0 04 F P PG PH
C
( ) .
100
1
2
F
C
: Inverter output frequency
P : Number of motor poles
PG : Number of PG pulses/rotation
PH : Single Phase = 1, Two-Phase = 4
0.04 : Response speed of 40ms