Mitsubishi Electric 800 Series Instruction Manual page 307

• For each signal, refer to the following table and assign the function by Pr.190 to Pr.196 (Output terminal function
selection).
Output Pr.190 to Pr.196 settings
signal
Positive logic
FU 4
FB 41
FU2 5
FB2 42
 Speed detection hysteresis (Pr.870)
• This function prevents chattering of the speed detection signals. When an output frequency fluctuates, the up to frequency
signal (SU) and the speed detection signals (FB and FB2) may repeat ON/OFF (chatter). Setting hysteresis to the detected
frequency prevents chattering of these signals.
Output
frequency
(Hz)
Pr.42
FB
ON
Example of the speed detection (FB) signal
NOTE
• In the initial setting, the FU signal is assigned to the terminal FU, and the SU signal is assigned to the terminal SU.
• All signals turn OFF during DC injection brake, tuning at start-up.
• Each signal's reference frequency differs by the control method.
Control method
V/F control
Advanced magnetic flux vector control Output frequency before the slip
PM motor control
• Setting a higher value in Pr.870 slows the response of frequency detection signals (SU, FB, and FB2).
• Changing the terminal assignment using Pr.190 to Pr.196 (Output terminal function selection) may affect the other
functions. Set parameters after confirming the function of each terminal.
Parameters referred to
Pr.190 to Pr.196 (Output terminal function selection)
306
5. PARAMETERS
5.8 (M) Monitor display and monitor output signal
Related
parameter
Negative logic
104 42, 43
141
105 50
142
Output frequency
Pr.870
ON
ON
FU, FU2
Output frequency
compensation
Frequency command value
(Hz)
Pr.870
SU output level
Pr.870
Pr.41
Set frequency
Pr.870
SU output level
Pr.870
SU signal
Example of the up to frequency (SU) signal
Compared frequency
Output frequency
Output frequency before the slip
compensation
Estimated frequency (actual motor speed)
page 297
ON ON
ON
FB, FB2, SU
Time