AW-Lake AW Gear Meters MX 9000, Руководство по установке, эксплуатации и техническому обслуживанию

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Each Limit can be set to trigger its output based on a certain flow rate or total set
point. This is often used to indicate if a flow rate is outside its intended limits or
if a certain total value has been reached in a batch application.
Rate Value
The limit output will be off if the incoming flow rate is below the programed Rate
Value and the output will be on if the incoming flow rate is equal to or above the
programmed Rate Value.
Limit Margin
The Limit Margin variable is programmed in engineering units and determines
whether the Rate Limit functions as an absolute limit or activates within a margin
or “window” around the programmed Rate Value. When the Limit Margin is
programmed as zero, the limit activates whenever the flow rate equals or exceeds
the programmed value. When you enter a Limit Margin value other than zero,
the limit is active whenever the selected flow rate is within the “window” of the
programmed Rate Value, plus or minus the MARGIN value. The programmed
Limit Margin must be less than the programmed Rate Value.
TOTAL / GRAND TOTAL Value
Enter the Total or Grand Total value at which the respective Limit output should
change state. When the Total or Grand Total is reset to zero, the limit pin
changes back to initial state.
Figure 21. Total/Grand Total Value