Instruction manual
5 8 Differential Control5 8 Differential Control
In certain applications controlling a second process such that its process
value always deviates from the first process with a constant value may be
required. Water tank 1 is 5.12 meters height and water tank 2 level is desirable
to be maintained at 1 meter lower than tank 1 level.
In certain applications controlling a second process such that its process
value
always deviates from the first process with a constant value may be
required.
Water tank 1 is 5.12 meters height and water tank 2 level is desirable
to
be maintained at 1 meter lower than tank 1 level.
FUNC= FULL
IN1, IN1L, IN1H : According to Sensor 1 signal
IN1U= PU
DP1= 2-DP
IN2, IN2L, IN2H : According to Sensor 2 signal
IN2U= PU
DP2= 2-DP
OUT1= REVR
O1TY= 4 20
PVMD= P1-2
SPMD=SP1.2
( Current signal has to be converted to a voltage
signal through a shunt resistor before sending to the controller input)
FUNC= FULL
IN1,
IN1L, IN1H : According to Sensor 1 signal
IN1U=
PU
DP1=
2-DP
IN2,
IN2L, IN2H : According to Sensor 2 signal
IN2U=
PU
DP2=
2-DP
OUT1=
REVR
O1TY=
4 20
PVMD=
P1-2
SPMD=SP1.2
(
Current signal has to be converted to a voltage
signal
through a shunt resistor before sending to the controller input)
Outlet
Outlet
From Controller Output
From Controller Output
4-20 mA Valve Control Output4-20 mA Valve Control Output
Water Tank 1Water Tank 1
Water Tank 2Water Tank 2
Level Sensor 1Level Sensor 1
Level Sensor 2Level Sensor 2
5.12 M Height5.12 M Height
4.12 M Height4.12 M Height
IN1 IN2
SV=1.00
PV=1.00
PV1=5.12
PV2=4.12
SV=1.00
PV=1.00
PV1=5.12
PV2=4.12
OUT1
Figure 5.13Figure 5.13
Differential Control ExampleDifferential Control Example
Adjust SP1(here it is 1.00) to control the difference between PV1 and PV2.
Choosing P1-2 for PVMD, the PV display will show the difference value (PV1-
PV2) between PV1 and PV2, and this value will be stabilized to the set point
If you need PV1 or PV2 instead of PV, you can use the Display Mode to
select PV1 or PV2 to be displayed. See . The above diagram
indicates PV2 instead of PV.
Section 3-24
Adjust SP1(here it is 1.00) to control the difference between PV1 and PV2.
Choosing P1-2 for PVMD, the PV display will show the difference value (PV1-
PV2) between PV1 and PV2, and this value will be stabilized to the set point
If you need PV1 or PV2 instead of PV, you can use the Display Mode to
select PV1 or PV2 to be displayed. See . The above diagram
indicates PV2 instead of PV.
Section 3-24
O1
O2
A1
F
ETR-3400