Mitsubishi Electric 800 Series Instruction Manual page 327

5.9.4 Analog input responsiveness and noise elimination
The frequency command responsiveness and stability are adjustable by using the analog input (terminals 1, 2, and 4) signal.
Pr.
74 Input filter time constant
T002
822 Speed setting filter 1
T003
832 Speed setting filter 2
T005
849 Analog input offset
T007 adjustment
 Block diagram
Terminal 1 (2, 4) input
 Analog input time constant (Pr.74)
• It is effective to eliminate noise on the frequency setting circuit.
• Increase the filter time constant if steady operation cannot be performed due to noise, etc. A larger setting results in slower
response. (The time constant can be between 0 and 8, which are about 2 ms to 1 s.)
 Analog speed command input time constant (Pr.822, Pr.832)
• Set the primary delay filter time constant to the external speed command (analog input command) by using Pr.822 Speed
setting filter 1.
• To change the time constant, for example, in a case where only one inverter is used to switch between more than one
motor, use Pr.832 Speed setting filter 2.
• Pr.832 Speed setting filter 2 is enabled when the RT signal is ON.
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5. PARAMETERS
5.9 (T) Multi-Function Input Terminal Parameters
Name Initial value
1
9999
9999
100%
RT-OFF
RT-ON
Setting range
0 to 8 The primary delay filter time constant to the analog
input is selectable. The higher the value, the lower
the responsiveness.
0 to 5 s Set the primary delay filter time constant to the
external speed command (analog input command).
9999 Use the Pr.74 setting.
0 to 5 s, 9999 Second function of Pr.822 (enabled when the RT
signal is ON)
0 to 200% Make the analog speed input (terminal 2) have an
offset. This prevents the motor from rotating by noise
to the analog input or another cause on the speed 0
command.
Pr.74
Pr.822 = 9999
Pr.822
Pr.822 ≠ 9999
Pr.832 = 9999
Pr.832
Pr.832 ≠ 9999
Description
Speed command