Yokogawa AXFA14G/C - Manual (Page 67)

IM 01E20F02-01E A-8
APPENDIX 2. INTEGRATOR (IT) BLOCK
A2.2.3 Converting Accumulation
This following describes an example of accumulation
conversion.
In accumulation conversion, the difference between the
value executed previously and the value executed this
time is integrated or accumulated. This conversion
applies when the output of a function block used as a
counter is input to the input process of the Integrator
block.
In order to convert the rate of change of an input to a
value with an engineering unit, the user must configure
the factor of conversion to the appropriate engineering
unit in the PULSE_VAL1 and PULSE_VAL2 param-
eters.
Moreover, the unit of IN_2 is standardized to that of
IN_1 in the same way as rate conversion. Thus, the
user must also set an appropriate value to
UNIT_CONV.
input1
counts number of pulse kg
kg/pulse
increment1
increment2
lb/pulse
input2
counts number of pulse lb kg
[Current read value] – [Previous read value]
[Current read value] – [Previous read value]
PULSE_VAL1(#19)
؋ [pulse value1]
PULSE_VAL2(#20)
؋ [pulse value2]
UNIT_CONV(#18)
؋ [conversion factor]
FA0203.EPS
Figure A2.3 Increment Calculation with Counter Input
A2.2.4 Determining the Input Flow Direction
The Integrator block also considers the input flow
direction. Information about the input flow direction is
contained in REV_FLOW1 and REV_FLOW2 (0:
FORWARD, 1: REVERSE).
In input processing, the sign of the value after rate and
accumulation conversion is reversed if the
REV_FLOW1 and REV_FLOW2 parameters are set to
REVERSE. When determination of the flow direction
of two input values is complete, these two inputs are
passed to the adder. The settings in REV_FLOW will
be retained even if the power is turned OFF.
A2.3 Adder
When input processing is complete, two arguments that
have been rate and accumulate converted will be
passed to the adder. The adder adds these two values
according to the option.
A2.3.1 Status of Value after Addition
If one of the statuses of two arguments is "Bad" or if
two of them are both "Bad," the status of the value
after addition becomes "Bad." In this case, the value of
"Good" just before the status changed to "Bad" is used
as the addition value (see A2.1).
When the statuses of two arguments are both "Good,"
the status of the value after addition becomes "Good."
In this case, the status of the value after addition will
be used for the status applied to integration.