SMAR CD600 Plus - Function 18 - Totalization (Tot); Operation

Library of Function Blocks
4.49
Function 18 - Totalization (TOT)
Operation
This block is used for flow totalization.
BLK 067/068/069/070
83/85
87/89
84/86
88/90
A
B
4 DIGITS + UPPER
MFL . Adt
100
4 DIGITS - LOWER
CLEAR
The block integrator provides a ΔI pulse whenever the result of the integration reaches the value
pre-adjusted in parameter
ATU.
The time required for the integrator to provide a pulse depends on ATU and on the instantaneous
flow rate, which is given by:
100
A . MFL
= Q
Where,
Q - Instantaneous flow rate in volume or mass engineering units per second.
MFL - Maximum flow rate in volume or mass engineering units per second. This should be
equivalent to A=100%.
MFL is adjusted in parameter AMFL.
A - Input A signal. It is the percent signal corresponding to the flow rate to be totalized.
EXAMPLE:
- Maximum flow rate = 3600 m
3
/h = 1 m
3
/s.
- The counter indicating totalized flow rate shall have an increment every 10 m
3
of fluid.
The Analog Totalization block shall be adjusted as follows:
- ATU = 10 (10 m
3
to generate one pulse)
-
AMFL = 1 (m
3
/s)
At maximum flow, the period between the counting pulses is given by:
10s =
/s
m
3
1
m
3
10
=
Q
ATU
= t
If the flow rate is 1800m
3
/h, which is equivalent to 0,5m
3
/s, the period between pulses would be:
20s =
0.5
10
= t
Therefore, for a steady flow rate of 1800m
3
/h, every 20s there will be an increment of the counter
and a pulse
ΔI will be available at output ΔI (83, 85, 87 and 89).
The output ΔI can only be connected to the input of the blocks F20 - "Batch Comparator" (input A)
and F19 - "Pulse Totalization Input" (input
B). If it is intended to use a counter external to the
CD600, the output ΔI shall be connected to input A of the Batch Comparator block. The first output
of blocks 073/074 (Address 99 and 103) provides pulses with a duration of one cycle time. These
pulses may be connected to a digital output block, that will drive an external counter.