Yokogawa digitalYEWFLO (DY-FF) - Manual (Page 112)

A6-5
IM 01F06F00-01EN
A6.3.3 Compensated Values
In computing equations 1) to 5) in APPENDIX
6.3.1 “Computing Equations” and 32) to 38)
in APPENDIX 6.3.2 “Enhanced Computing
Equations”, the value “f” is restricted by the COMP_
HI_LIM or COMP_LO_LIM parameter. In this case,
the value “f” is treated as follows:
Calculation formura 1) to 5)
If f > COMP_HI_LIM:
f = COMP_HI_LIM
If f < COMP_LO_LIM:
f = COMP_LO_LIM
Calculation formura 32) to 38)
If Correction value > COMP_HI_LIM:
Correction value = COMP_HI_LIM
If Correction value < COMP_LO_LIM:
Correction value = COMP_LO_LIM
A6.3.4 Average Calculation
In computing equation 6) in APPENDIX 6.3.1
“Computing Equations”, the average of input value
is calculated. Here, it is necessary to obtain the
number of inputs, N. For this, determination is
made to see if the sub-status of each input is “Not
Connected.” Note that the main inputs may be
accepted if IN or IN_LO is not in “Not Connected”
sub-status. In this case, the number of inputs that
are not in “Not Connected” sub-status is regarded
as “N.”
A6.4 Output Section
After executing the computing equation, the block
applies a gain to the calculated result and then adds
a bias to it.
It then substitutes the result into PRE_OUT and
if the mode is in AUTO, the value of PRE_OUT is
taken as OUT.
PRE_OUT = func × gain + bias
where func: result of computing equation
execution
OUT = PRE_OUT (when the mode is in
AUTO)
Next, the block performs limitation processing
(OUT_HI_LIM, OUT_LOW_LIM). This processing
is described as follows with respect to the value of
PRE_OUT.
If PRE_OUT > OUT_HI_LIM:
PRE_OUT = OUT_HI_LIM
The “high limited” processing is
applied to the status of PRE_OUT.
If PRE_OUT < OUT_LO_LIM:
PRE_OUT = OUT_LO_LIM
The “low limited” processing is
applied to the status of PRE_OUT.