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502 010 05
8.2
Batch control using the PD 210 display
Start
The PD 340 Flow Transmitter has a built-in batch control function, and can therefore be
easily used to control the dosing of a specified volume. The requested volume is keyed into
"SETPOINT" on the PD 210. Input1 on the PD 340 is used to start the batch control.
Output2 controls the dosing valve or pump. The Volume2 counter shows the dosed volume.
When the batch control function is used, the built-in flow regulator cannot be used.
1
Input 1
Setp. . . .
2
Vol. 2 . . . . . . . .
3
Output 2
The function of the system
First, the requested volume is keyed into "SETPOINT". The dosing will start when Input1 is
activated. This will clear the Volume2 counter and Output2 switches on. The valve or pump
controlling the flow must be activated by the relay. When the liquid starts to flow, "Volume2"
will count up, and when it is equal to the setpoint, Output2 will switch off. Because of the
reaction time of the valve or pump, the flow will not stop immediately after Output2 is
switched off. Consequently the actual dosed volume is a little higher than the setpoint. This
after-flow is fairly constant if the reaction time and the flow rate are constant, and therefore
it is possible to compensate for that by reducing the setpoint with the volume of the after-
flow. The volume of this after-flow can be calculated as [Volume2 - setpoint].
Programming the batch control
To obtain the requested functions the PD 340 must be programmed as shown below. When
programming the Flow Transmitter, the Program Enable Switch on the terminal board must
44/55
PD 210
DISPLAY FOR
7
8
9
FLOW TRANSMITTER
=
E
4
5
6
1
2
3
FLOW
TEMP.
VOL.1
SETP.
TEST
T.C.
CE
0
,
+/-
VOL.2
FLOW
PD 210
4
5
Flow Transmitter, PD 340
551 117 01
551 118 01
Manual
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