Brainchild BTC-2500 - Dual Set Point; PID

UM25001C
5 9 Dual Set Point / PID5 9 Dual Set Point / PID
The BTC-2500 will switch between the two PID sets based on the process
value, the set point or either of the event input. As the control ramps up to the
higher process value, the process characteristics changes. As this happens,
the original PID values are no longer valid. To achieve optimal control over the
entire range, a second PID set is used.
The BTC-2500 will switch between the two PID sets based on the process
value,
the set point or either of the event input. As the control ramps up to the
higher
process value, the process characteristics changes. As this happens,
the
original PID values are no longer valid. To achieve optimal control over the
entire
range, a second PID set is used.
Example 1: Single Set Point / Dual PIDExample 1: Single Set Point / Dual PID
A heat treating furnace is used over the range of 400 C to 1200 C.A heat treating furnace is used over the range of 400 C to 1200 C.
( 1 ) Set the following parameters in the Setup menu:( 1 ) Set the following parameters in the Setup menu:
FUNC= FULL
A1FN= PV1H
A1MD= NORM
EIFN= PID2
PVMD= PV1
SPMD= MINR
FUNC= FULL
A1FN=
PV1H
A1MD=
NORM
EIFN=
PID2
PVMD=
PV1
SPMD=
MINR
( 2 ) Adjust the following parameters in the User menu:( 2 ) Adjust the following parameters in the User menu:
A1SP= 800 C
A1HY= 1.0 C
PL1= 100 ( % )
RAMP: According to the process requirement
SP1: According to the process requirement
A1SP= 800 C
A1HY=
1.0 C
PL1=
100 ( % )
RAMP:
According to the process requirement
SP1:
According to the process requirement
( 3 ) Tune first PID set at SP1= 500 C and tune second PID set at SP1=1100 C,
or set the proper values for PB1, TI1, TD1, PB2, TI2 and TD2 directly
according to the previous records to eliminate auto-tuning sequence.
( 3 ) Tune first PID set at SP1= 500 C and tune second PID set at SP1=1100 C,
or
set the proper values for PB1, TI1, TD1, PB2, TI2 and TD2 directly
according
to the previous records to eliminate auto-tuning sequence.
The circuit diagram and its temperature profile are shown as follows :The circuit diagram and its temperature profile are shown as follows :
To
Furnace
Heater
To
Furnace
Heater
Heater
Power
Input
Heater
Power
Input
AC powerAC power
Alarm 1 controls
Event input
Alarm 1 controls
Event
input
Figure 5.14Figure 5.14
Dual PID FurnaceDual PID Furnace
Process ValueProcess Value
PID Crossover ValuePID Crossover Value
Use PID 1Use PID 1
Use PID 2Use PID 2
Time
C
800
Figure 5.15Figure 5.15
Dual PID CrossoverDual PID Crossover
94
12
34
5
8910
11
67
12
13
14