Mitsubishi Electric FR-A700 Technical Manual page 380

(5) Parameter details
Bias
[C2(Pr. 902)]
0
Frequency setting signal
When ratio ([Pr. 128 = "42, 43"]) is selected for
addition method, PID control × (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 [C2 (Pr. 902) Terminal 2 frequency setting
bias frequency]. The frequency setting signal is set to 0
to 60Hz in the range of 0 to 100% in the initial setting.
The ratio is (×100%) when the main speed is 60Hz
and (×50%) when 30Hz.
[Pr. 128 Setting] PID Action
40 Reverse action
41 Forward action
42 Reverse action
43 Forward action
Action of [ Pr. 129 PID proportional band ], [ Pr. 130 PID
integral time ], [ Pr. 131 PID upper limit ], [ Pr. 132 PID
lower limit ], [ Pr. 134 PID differential time ] is the same
as PID control. For the relationship of controlled
variable (%) of PID control and frequency, 0% is
equivalent to the set frequency of [ Pr. 902 ] and 100%
to [ Pr. 903 ] .
For the [ Pr. 133 PID action set point ] setting, set
frequency of [ Pr. 902 ] is equivalent to 0% and [ Pr.
903 ] to 100%. When 9999 is set in [ Pr. 133 ], 50% is
the set point.
*1 PID control stops when RH, RM, RL, and REX signals
(for multi-speed operation) or JOG signal is input during
normal PID control. However, PID control continues
when those signals are input during dancer control since
these are treated as speed commands.
*2 The second acceleration/deceleration time set in [Pr. 44,
45] is the acceleration/deceleration time for the main
speed command during dancer control, and it does not
function as second function.
*3 Dancer control (PID control) is invalid when switchover
mode is selected with [Pr. 79=6].
*4 Speed command to terminal 4 by turning AU signal ON is
invalid during dancer control.
*5 Acceleration/deceleration of main speed command
follows the frequency increase/decrease made by analog
input. Therefore, the following situations may occur:
• SU signal may stay ON even though start signal is
switched ON/OFF. (Always in constant speed status)
• When the start signal is OFF, the DC brake does not
activate at the frequency set in [
frequency between [ Pr. 13
Initial value
Gain
[Pr. 125]
100%
Addition Method
Fixed
Ratio
Pr.10 ], but at the smaller
] setting or 0.5Hz.
Even when C4 [(Pr. 903)] is set to other than 100%,
the frequency setting signal is considered as 100%.
Even when [C3 (Pr. 903)] is set to other than 0%, the
frequency setting signal is considered as 0%.
When [C2 (Pr .902)] is set to other than 0Hz, the
frequency setting signal is 0% when [C2 (Pr. 902)] is
less than the set frequency.
Turning X14 signal ON/OFF during operation by
assigning X14 signal results in the following
operation.
When X14 signal is ON: Uses output frequency
unchanged as the main speed command and
continues operation by dancer control.
When X14 signal is OFF: Ends dancer control
and continues operation at the set frequency.
Set Point Measured Value
Pr. 133 Terminal 4
• The value of "speed command + PID control", which is
constantly changing, is displayed in the set frequency
monitor.
*6 The main speed
decelerates by the [Pr. 44, 45] settings. Output frequency
accelerates/decelerates by the [Pr. 7, 8] settings.
Therefore, when the set time in [Pr.7, 8] is longer than the
set time in [Pr. 44, 45], the set time in [Pr. 7, 8] is the
acceleration/deceleration time of the output frequency.
*7 Integral term is limited by the smaller value between
100% and the PID manipulated variable (%) converted
from the linear interpolated [Pr.1 Maximum frequency] by
[Pr. 902, 903].
Although the output frequency is limited by the minimum
frequency, the action of the integral term is not limited.
414
PARAMETER
Main Speed Command
Speed command for each
operation mode
setting frequency accelerates/