AW Gear Meters RT-15 - Manual (Page 27)

RT‐15 Flow Monitor
Operation and Programming Manual
26
LIMITS Programming
Program the Limits from the LIMIT display screen. You can assign L1 and L2 to any of these
functions.
 RATE A GT
 RATE A PL
 TOTAL A
 CYCLE OUT (Pulse Output)
RATE Limits/Limit MARGIN
To operate a limit based on RATE, select a RATE A function based on pulse length or gate time
measurement. The MARGIN variable is programmed in engineering units and determines whether the
limit functions as an absolute limit or activates within a margin or “window” around the programmed
RATE limit. When the MARGIN is programmed as zero, the limit activates whenever the selected RATE
equals or exceeds the programmed value. When you enter a MARGIN value other than zero, the limit is
active whenever the selected RATE is within the “window” of the programmed RATE limit value, plus or
minus the MARGIN value.
TOTAL Limits
To operate a limit based on the JOB TOTAL, select TOTAL A for the Limit function. The limit activates
whenever the selected TOTAL equals or exceeds the programmed value. See BATCH TOTAL Display
Mode on page 28 for alternate setup of total limits.
CYCLE OUT (Pulse Output)
The CYCLE OUT limit function provides an incremental output signal for a remote totalizer, typically at a
lower resolution and frequency. You can assign either or both limits to a CYCLE OUT function. Assigning
a limit to the CYCLE OUT function toggles the state of the limit output whenever Job TOTAL A
increments by the programmed cycle amount. The output remains ON until the cycle amount
accumulates and does not turn OFF until the cycle amount accumulates again as represented in the
diagram on page 27. The total accumulated between a rising and falling edge is the cycle value. The total
accumulated between any two rising edges is twice the cycle value. You enter the cycle value in
engineering units corresponding to the programmed KFT and decimal location.
Do not program a cycle amount that produces more than ten pulses per second (10 Hz).
Consider the maximum flowrate to determine the resulting output frequency. The frequency produced
(in Hz.) is the actual flow rate in Engineering Units per Minute divided by 120, divided by the CYCLE
AMOUNT.
Caution