Yokogawa EJX930A - Manual (Page 87)

<Appendix 2. Integrator (IT) Block>
A2-3
IM 01C25T02-01E
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
parameters.
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.ai
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.