回測不能使用GetSymbolField ???

如附圖的回測設定及失敗結果

隨寫簡單的script如下:

警示A --- XmVixBt

   Value1 = GetSymbolField("VIX.TF","收盤價");

   Condition1 = Value1 < 20 and Close > Highest(High[1], 20);        

   if Condition1 then   

      Ret = 1;

警示B --- XmVixSt

   Value1 = GetSymbolField("VIX.TF","收盤價");

   Condition2 = Value1 > 20 and Close < Lowest(Low[1], 20);     

   if Condition2 then     

      Ret = 1;