The calculation results show "NaN"，pls help me
Posted: Wed Aug 09, 2017 2:07 am
I have a project used PCS7V8.2 & IL & 315-2DP,
and I create a FB like "Lag" in APL.
The SCL program is shown as follows：
If the input ("IN") is fixed in a negative number always , and a few hours later,the output("OUT") shows “NaN”.
Why?
Is floating-point calculation overflow ？
and I create a FB like "Lag" in APL.
The SCL program is shown as follows：
Code: Select all
OUT := SEL(G:=LAG_T<=0.0,IN0:=IN + (sr_lv_out-IN)*(EXP(-Sample_T/LAG_T)),IN1:=IN);
sr_lv_out := OUT;Why?
Is floating-point calculation overflow ？