Burkert Type 8611 - Manual (Page 56)

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FunctionsoftheConfigurationLevel
12.3.5. 2P – T - Quasi-continuous 2-state control with open/
closed valves
This function can be used to implement quasi-continuous controls using open/closed valves.
Here, unlike in purely open/closed controls that only provide for the states open or closed, the control time for the
opening or closing is varied proportionally to the set-point/actual value deviation. The valves are controlled via the
transistor output of the controller.
T 8611
Pt 100
Controller setting:
MODE = T, 2P – T, NC, PT
NC valve
Figure 39: Example of a 2-state temperature control with open/closed valve
Setting the quasi-continuous 2-state control in the menu:
Selection of
control variable
MODE
0001
CODE
selection of
operating principle
enter
minimum
control time
selection of
2-state control
Continue with
selection of process value input
see Figure 27
2P – T
NC
VLV1
NO
VLV1
0001
TMN1
Figure 40: 2P – T; 2-state control / operating principle
display description
2P – T Quasi-continuous 2-state control with time-proportional control for opening and closing.
VLV1 Control of valve 1 (output BO3)
NC Valve with operating principle "closed with no current" (normally closed).
NO Valve with operating principle "opened with no current" (normally open).
TMN1 Minimum control time in ms
Table 17: Display 2P – T; quasi-continuous 2-state control / operating principle
english
Type 8611