- 04 Jul 2023
- 2 Minutes to read
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How to apply logical rules to a pump
- Updated on 04 Jul 2023
- 2 Minutes to read
- Print
Logical rules can be added to an open-channel pump to enable its operation to be determined by specified situations.
This could include specifying the pump to turn on based on the water level at a given reference point, for instance.
Note:
This guide covers the minimum data required. Several optional settings are also available for logical rules, please see the Rules section of the technical reference for further details.
Steps
Open the pump unit to which you are applying the rule(s) and navigate to the Control Data tab.
Use the drop-down to change the Control Method to LOGICAL. In the table provided, set the Mode to AUTO to use automatic mode from the start (time 0). When in automatic mode the unit will be driven by the rules you define. Also set the Pump Mode in this row to specify whether the pump should be on, off, or stopped at the start (time 0).
Navigate to the Rules sub-tab to add your logical rules. Click New Rule and the Rule editor will open in a new window. The rule must be of the form:
IF (xxx)
THEN PUMP = ON or THEN PUMP = OFF or THEN PUMP = STOPPED
END
Where xxx is a logical statement that can be evaluated as true or false. An example is provided below.
Repeat step 3 as required. Following 1 or more of the IF rules, an ELSE condition can be optionally provided to cover all other eventualities:
ELSE PUMP = ON or ELSE PUMP = OFF or ELSE PUMP = STOPPED
END
An ELSE rule must be located as the final rule in the list.
Example usage: controlling the operation of a pump according to the water level at the two gauge points A1 and A2.
- Rule1 turns the pump off (so it acts as a simple junction) when the water level is sufficiently low at both gauge points
- Rule2 turns the pump on when the water level at A1 is greater than 10.0m and the water level at A2 is 12.2m or lower
- Rule3 sets the pump to stop (so no water can flow through) in other situations (i.e. when the water level is sufficiently high at both gauge points)
RULE1
IF(LEVEL(A1).LE.10.0.AND.LEVEL(A2).LE.12.2)
THEN PUMP=OFF
END
RULE2
IF(LEVEL(A1).GT.10.0.AND.LEVEL(A2).LE.12.2)
THEN PUMP=ON
END
RULE3
ELSE PUMP=STOPPED
END
Click OK to save and close the unit. Don't forget to also Save these changes to the network.
Note:
Each rule can provide a maximum of one action to be applied to the unit (pump, in this case), however ALSO statements can be added to define rules for global variables.
You can also apply logical rules to a sluice or gated weir and apply logical rules to an abstraction unit.