Endress+Hauser RIA452 Mode D'emploi page 131

RIA452
Thus, the number of free relays available is reduced accordingly. The operating menus for these
inputs/outputs are then hidden.
Set count B (LV B) defines the preliminary switchoff, Set count A (LV A) defines the main
switchoff. Limit value (or start value, see "Pre-counter" function on Page 45) for LV A and
preliminary alarm value for LV B are freely configurable
The positive counting direction is defined as follows: starting at the fixed starting value of zero,
count up until the set limit value is reached (Set count A).
The negative counting direction is defined as follows: starting at the configurable starting value
(Set count A), count down until the fixed limit value of zero is reached.
Resetting with simultaneous counter restart takes place by means of digital input 1 (Digital
Inp.1). Edge Digital Inp.1: Low-High = reset and start counter.
!
Note!
Display of the preset counter can be selected under DISPLAY/M2 É "Ref. num" = "Batch"
Calculation formula for flow measurement
If you selected "Formula" under Calc. flow for flow measurement, the flow is calculated using
the following formula:
Where:
• Q: Flow rate in m
• C: Scaling constant
• h: Headwater level
• α, β: Flow exponent
• γ: Weighting factor
!
Note!
The scaling constant C must always refer to Q in m
in another flow unit.
Examples:
• Q in l/h with C = 2.11
1 l/h = 0.001 m
C = 2.11 * 0.001 = 0.00211
• Q in USKgal/s with C = 0.35
1 USKgal/s = 13627.4444 m
C = 0.35 * 13627.4444 = 4769.60554
A table with values for converting the various flow units to m
6.3.7 Pulse output - PULSE OUT/M19
All the possible settings for the pulse output can be found in this menu item. This menu item
can only be selected if your device is fitted with this option.
Endress+Hauser
3
/h
3
/h
3
/h
3
/h, i.e. C has to be converted if C is available
3
/h is provided in the appendix.
Commissioning
131