<Appendix 3.
Arithmetic (Ar) Block>
257
IM 01E21A02-03EN
Example
RANGE_LO 20
RANGE_HI 300
In the above case, the followings are established:
IN=310,IN_LO=20 => PV=310
IN=230,IN_LO=20 => g=(230−20)/(300−20)=0.75
PV=0.75x230+(1−0.75)x20=177.5
IN=90,IN_LO=20 => g=(90−20)/(300−20)=0.25
PV=0.25x230+(1-0.25)x20=37.5
IN=19,IN_LO=10 => PV=10
A3.2.2 Auxiliary Inputs
There are bias and gain parameters for the IN_1, IN_2, and IN_3 auxiliary inputs. The following
shows the equation using them.
t_i=(IN_i+BIAS_IN_i)xGAIN_IN_i
The bias parameter is used for calculating absolute temperature or absolute pressure, while the
gain parameter is used for normalization of square root extraction.
A3.2.3 INPUT_OPTS
INPUT_OPTShasanoptionthathandlesaninputwith“uncertain”or“bad”statusasa“good”
status input.
Bit Function
0 HandlesINasa“good”statusinputifitsstatusis“uncertain”.
1
HandlesIN_LOasa“good”statusinputifitsstatusis
“uncertain”.
2 HandlesIN_1asa“good”statusinputifitsstatusis“bad”.
3 HandlesIN_1asa“good”statusinputifitsstatusis“uncertain”.
4 HandlesIN_2asa“good”statusinputifitsstatusis“bad”.
5 HandlesIN_2asa“good”statusinputifitsstatusis“uncertain”.
6 HandlesIN_3asa“good”statusinputifitsstatusis“bad”.
7 HandlesIN_3asa“good”statusinputifitsstatusis“uncertain”.
8 to 15 Reserved
Thereareoptionscalled“INUseuncertain”and“IN_LOUseuncertain”fortheINandIN_LO
inputs.Whentheseoptionsarevalid,INandIN_LOareinternallyinterpretedas“good”INand
IN_LOeveniftheirstatusesare“uncertain”.(Thereisnooptionfor“bad”status.)
FortheIN_1,IN_2,andIN_3auxiliaryinputs,thereareoptionsknownas“IN_iUseuncertain”
and“IN_iUsebad”.Iftheseoptionsarevalid,anIN_iwith“uncertain”or“bad”statusisinternally
interpretedasa“good”IN_i.
* Theexceptionisthatifeachinputstatusis“Bad.NotConnected”,INPUT_OPTSdoesnot
apply and the input remains bad.
To Next Page
Loading...
Need help?
General
