To close an open trade to start a new one:

IF MyLongConditions  THEN          //LONG
   IF LongOnMarket  THEN
      SELL AT MARKET               //close any open LONG  position
   ENDIF
   BUY 1 CONTRACT AT MARKET        //close any SHORT open position and enter a new LONG one
ENDIF
IF MyShortConditions THEN          //SHORT
   IF ShortOnMarket THEN
      EXITSHORT AT MARKET          //close any open SHORT position
   ENDIF
   SELLSHORT 1 CONTRACT AT MARKET  //close any LONG open position and enter a new SHORT one
ENDIF

To count X periods before entering a new trade:

ONCE Count    = 0
ONCE MinCount = 2
IF (Not OnMarket AND OnMarket[1]) OR (StrategyProfit <> StrategyProfit[1]) THEN  //check thare was a trade open the previous bar and not any longer....
   Count = 1                                                                     //... to start counting periods (bars)
ELSE
   Count = Count + 1                                                             //increment Count at each new period (bar)
ENDIF
IF OnMarket THEN
   Count = 0
ENDIF
IF MyLongConditions  AND Not OnMarket AND ((Count = 0) OR Count > MinCount)) THEN
   BUY 1 CONTRACT AT MARKET                                                      //LONG
ENDIF
IF MyShortConditions AND Not OnMarket AND ((Count = 0) OR Count > MinCount)) THEN
   SELLSHORT 1 CONTRACT AT MARKET                                                //SHORT
ENDIF