Yokogawa EJX930A - Manual (Page 112)

A4-1
IM 01C25T02-01E
Appendix 4. Arithmetic (AR) Block
The Arithmetic (AR) block switches two main inputs of different measurement ranges seamlessly and
combines the result with three auxiliary inputs through the selected compensation function (10 types) to
calculate the output.
A4.1 Arithmetic Function Block Schematic
The diagram below shows the Arithmetic block schematic.
IN
IN_LO
IN_1
IN_2
IN_3
RANGE_LO
RANGE_HI
RANGE
EXTENSION
FUNCTION
(IN_1+BIAS_IN_1) * GAIN_IN_1
(IN_2+BIAS_IN_2) * GAIN_IN_2
(IN_3+BIAS_IN_3) * GAIN_IN_3
BIAS_IN_i
GAIN_IN_i
ARITH_TYPE
BAL_TIME
PV
t_1
t_2
t_3
ALGORITHM TYPE
COMP_LO_LIM
COMP_HI_LIM
func
* GAIN
+ BIAS
OUT_HI_LIM
MAN·O/S
OUT
OUT_LO_LIM
PRE_OUT
FA0401.ai
Figure A4.1 AR Block
The Arithmetic block is divided into three sections:
• Input section: Makes a go/no-go decision on the use of an input value, switches the range, and
determines the PV status.
• Computation section: Makes calculations through ARITH_TYPE.
• Output section: Applies gain multiplication and bias addition to the calculated result to perform limitation
processing for output.
* The range extension function compensates the IN and IN_LO input values when two devices with different
ranges are connected, to make smooth input switching.