Mitsubishi Electric 800 Series Instruction Manual page 513

(A) Application parameters
Selection of additive method for PID calculation result
• When ratio is selected as the additive method (Pr.128 = "42, 43"), PID calculation result  (ratio of main speed) is added to
the main speed.
The ratio is determined by the Pr.125 Terminal 2 frequency setting gain frequency and Pr.902 Terminal 2 frequency
setting bias frequency settings. In the initial status, 0 to 60 Hz is set for 0 to 100%. Thus, 60 Hz main speed is regarded
as 100%, and the 30 Hz main speed is regarded as 50%.
NOTE
• Even if Pr.903 is set to other than 100%, the frequency setting signal is treated as 100%.
• Even if Pr.902 is set to other than 0%, the frequency setting signal is treated as 0%.
• If Pr.902 is set to other than 0 Hz, the frequency setting signal is 0% at the Pr.902 frequency setting or below.
Setting the upper and lower limits of the PID manipulated amount
(Pr.1134, Pr.1135)
• Set the upper and lower limits of the PID manipulated amount.
• The upper limit of the manipulated amount is the frequency obtained by adding the value resulting from frequency
conversion of Pr.1134 to the main speed.
The lower limit of the manipulated amount is the frequency obtained by subtracting the value resulting from frequency
conversion of Pr.1135 from the main speed.
Output frequency
Input/output signals
• The following signals can be used by assigning functions to Pr.178 to Pr.189 (Input terminal function selection) and
Pr.190 to Pr.196 (Output terminal function selection).
• Input signal
Signal Function
PID control valid
X14
terminal
PID forward/reverse
X64
action switchover
PID P control
X72
switchover
512
PARAMETERS
Output frequency
60Hz
Bias
Pr.902
0
Pr.178 to Pr.189
setting
When this signal is assigned to the input terminal, PID control is enabled when
14
this signal is ON.
PID control is switched between forward and reverse action without changing
64
parameters by turning ON this signal.
72 Integral and differential values can be reset by turning ON this signal.
Initial value
100%
Frequency setting signal
Output frequency considering upper/lower limit
of PID manipulated amount
Gain
Pr.125
Upper limit of PID manipulated amount
Main speed
Lower limit of PID manipulated amount
Time
Description