Revision 4 Foundation Fieldbus RMA803 Remote Indicator User's Guide Page 71
If the input option is Accum
The Integrator block determines the number of additional counts from the counter input readings
from the last execution.
The difference in count is determined as follows:
• If the difference between the reading in one cycle and the reading in the preceding cycle is less
than 500,000 or greater than (- 500,000), the difference must be taken as the variation.
• If the difference between the reading in one cycle and the reading in the preceding cycle is
greater than or equal to (+500,000), add (-1,000,000), use the result as the variation.
• If the difference between the reading in one cycle and the reading in the preceding cycle is more
negative than or equal to (-500,000), add (+1,000,000), use the result as the variation.
The variation of each input must be multiplied by the value, in engineering units, of each pulse given
by PULSE_VAL1 or PULSE_VAL2, as appropriate. The result is the increment in engineering units
of, for example, mass, volume or energy per block execution.
Net Flow
The Net Flow is calculated by considering the direction of flow. The direction of the flow is
calculated by selecting the parameters REV_FLOW and REV_FLOW2. When the status is set to
True for any of these two parameters, the direction of the flow for that input is considered
(Increment is negative) to be negative and the net flow is calculated by adding the increments for
that cycle of execution.
In order to integrate the difference between the inflow and outflow of a tank, for example, the
second one can be assigned to be negative.
The Net Flow direction to be considered in the totalization is defined in INTEG_OPTS. The
following options are available:
• FORWARD = Only positive flows (after application of REV_FLOWi) are totalized. The
negative values must be treated as zero. FORWARD is selected when the bit corresponding to
Forward is set to True.
• REVERSE = Only negative flows are totalized. The positive values must be treated as zero.
The option bit Reverse must be set to True.
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