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4-25
Chapter 4. Functions
z
MV change limit
The amount of MV change can be limited for each control loop.
Item (bank)
Display
Description
Initial value
MV increase change limit
(CONTROL bank)
MENU > Control
MV increase change limit
0.0000: No limit
0.0001 to 10000 %/s
0.0000
MV decrease change limit
(CONTROL bank)
MENU > Control
MV decrease change limit
0.0000: No limit
0.0001 to 10000 %/s
0.0000
•
Set the maximum amount of MV change per second using an absolute value (%).
However, the MV change per sampling cycle is limited to the set value multiplied
by the number of seconds of the sampling cycle.
For example, if 5.0 (%/s) is set while the sampling cycle is 0.01 s, the MV change
is limited to a maximum of 0.05 %.
If 0 is set, there is no limit for MV change.
•
If ON/OFF control is set, the MV change limit is invalid.
z
PID control
The settings related to PID control can be set for each control loop.
Item (bank)
Display
Description
Initial value
P (Proportional band)
(PID bank)
MENU > PID
P (Proportional band)
0.1000 to 3200.0 %
5.0000
I (Integral time)
(PID bank)
MENU > PID
I (Integral time)
0.0000 to 32000 s
120.00
D (Derivative time)
(PID bank)
MENU > PID
D (Derivative time)
0.0000 to 32000 s
30.000
RE (Manual reset)
(PID bank)
MENU > PID
RE (Manual reset)
-10.000 to +110.00 %
50.000
OL (MV low limit)
(PID bank)
MENU > PID
OL (MV low limit)
-10.000 to +110.00 %
0.0000
OH (MV high limit)
(PID bank)
MENU > PID
OH (MV high limit)
-10.000 to +110.00 %
100.00
Proportional band for cooling
(PID bank)
MENU > PID
Cool P (Proportional band)
0.1 to 3200.0 %
5.0000
Integral time for cooling
(PID bank)
MENU > PID
Cool I (Integral time)
0.0 to 32000 s
120.00
Derivative time for cooling
(PID bank)
MENU > PID
Cool D (Derivative time)
0.0 to 32000 s
30.000
MV low limit for cooling
(PID bank)
MENU > PID
Cool OL (MV low limit)
-10.0 to +110.0 %
0.0000
MV high limit for cooling
(PID bank)
MENU > PID
Cool OH (MV high limit)
-10.0 to +110.0 %
100.00
•
There are 8 groups of PID settings for each control loop.
•
If the MV low limit is greater than the MV high limit, the low limit and the high
limit are automatically interchanged.
•
When heating/cooling control is set, the settings for the proportional band for
cooling, integral time for cooling, derivative time for cooling, MV low limit for
cooling, and MV high limit for cooling are enabled.
•
Manual reset uses parameters common to the PID control reverse action, PID
control direct action, and PID control heating/cooling action. It is enabled when
integral time = 0.0000 or when the derivative time for cooling = 0.0000.