7-15
Chapter 7. PARAMETER SETUP
• The AT LED lights while reviewing the
B
R
value when set to 2.
• Do not set to 2 when normal control is not being carried out due to
inappropriate tuning of the PID constant, for example.
Also, hunting is more likely to occur when
B
R
is set to a large
value on quick-starting lines. Set the
B
R
value to 0 then to 2.
• On heat/cool models, smart-tuning does not function.
●
●
2
P
I
D
(2 degrees of freedom)
0: 2 degrees of freedom is disabled.
1: 2 degrees of freedom is enabled.
• 2 degrees of freedom is a function for improving the response to
disturbance during setup without losing conventional characteris-
tics at rise (or fall).
When set to 1, optimum PID constants can be set individually for
inhibiting disturbance in addition to conventional the PID con-
stant.
These constants are set automatically during AT execution, and is
memorized. They can also be set and changed independently.
In particular, on 2G output models, suppressing changes in MV to
lessen the frequency of motor operation during setup, and manu-
ally applying weak PID differential for inhibiting disturbance to
lengthen service life, for example, proves effective.
• These PID are switched automatically by applying fuzzy rules on
the slope between deviation and PV.
• When
I
(reset time) is set to 0, control is carried out without inte-
gration in all states regardless of the setting value of
D
I
(distur-
bance inhibit reset time).
• On heat/cool models, 2 degrees of freedom does not function.
●
●
D
I
F
F
• ON-OFF control differential
When P is set to 0.0 on both 0D and 6D output models, control is set
to ON-OFF control, and operational period at that time is set.
Differential
gap
PV
OFF
ON
Reverse action
Differential
gap
PV
OFF
ON
Direct action
SP
SP
