AW Gear Meters RT-30EX - Manual (Page 26)

RT-30EX Flow Transmitter
Operation and Programming Manual
26
RT-30EX User Manual, Rev. 1.7 02/07/2012
Limit outputs
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 Limits/Limit MARGIN
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
C YC LE A M O UN T C YC LE A M O UN T C YC LE A M O UN T C YC LE A M O UN T C YC LE A M O UN T
LIM IT O N LIM IT O N
LIM IT O FF LIM IT O FF LIM IT O FF
2 x C YC LE A M O UN T
C YC LE O UT (PULSE O UTPUT) Lim it Fu n c t io n
Select Limit Type
> ______________ <
~Rate
~Total
~Grand Total
UP/DN ENT
Scaling menu
Limit Types
Rate Value
00000.00 GPM
Limit Margin
> 00000.00 GPM Rate Value
> 00000.00 GPM
Limit Margin
00000.00 GPM
ENT ENT
Figure 31: Cycle Output definition
Figure 32: Limit output sources
Figure 33: Rate limit variables