{
Calculate time since tag switch on
}
procedure CalcWdtTime(tag:Integer; var wdt:Real);
begin
 if iGetTag(tag)<>0 then begin
  if wdt<=0 then wdt:=msecnow;
 end else begin
  wdt:=0;
 end;
end;
{
Calculate time since tag switch on
}
function GetWdtTime(wdt:Real):Real;
begin
 if wdt>0 then GetWdtTime:=msecnow-wdt else GetWdtTime:=0;
end;
