<Appendix 3. Arithmetic (Ar) Block>
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IM 01E21A02-03EN
10) Polynomial computation
func = PV + t_1 x PV
2
+ t_2 x PV
3
+ t_3 x PV
4
* Precaution for computation
Division by 0
=> If a value is divided by “0”, the calculation result is interpreted
as 10
37
and, depending with core, a plus sign is added to it
Negative square root => The square root of an absolute value is extracted and a minus
sign is added to it.
A3.3.2 Compensated Values
In computing equations 1) to 5) in A3.3.1, 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:
If “f” > COMP_HI_LIM
f = COMP_HI_LIM
If “f” < COMP_LO_LIM
f = COMP_LO_LIM
A3.3.3 Average Calculation
In computing equation 6) in A3.3.1, the average of input value is calculated. Here, since it is
necessary to obtain N, the number of inputs, determine 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”.
A3.4 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 x 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_LO_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.
