//+------------------------------------------------------------------+
//|                                                   PairSignal.mq4 |
//|                                              Copyright 2018, AM2 |
//|                                      http://www.forexsystems.biz |
//+------------------------------------------------------------------+
#property copyright "Copyright 2018, AM2"
#property link      "http://www.forexsystems.biz"
#property version   "1.00"
#property strict
#property indicator_chart_window

input string s1="EURUSD";
input string s2="USDCHF";

input string IndName="PriceBorder";
input string TimeFrame="All tf";
input int HalfLength=61;
input int Price=0;
input double ATRMultiplier=2.6;
input int ATRPeriod=110;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- indicator buffers mapping

//---
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
//---
   double up1=iCustom(s1,0,IndName,TimeFrame,HalfLength,Price,ATRMultiplier,ATRPeriod,1,0);
   double dn1=iCustom(s1,0,IndName,TimeFrame,HalfLength,Price,ATRMultiplier,ATRPeriod,2,0);
   double op1=iOpen(s1,0,0);
   double cl1=iClose(s1,0,0);

   double up2=iCustom(s2,0,IndName,TimeFrame,HalfLength,Price,ATRMultiplier,ATRPeriod,1,0);
   double dn2=iCustom(s2,0,IndName,TimeFrame,HalfLength,Price,ATRMultiplier,ATRPeriod,2,0);
   double op2=iOpen(s2,0,0);
   double cl2=iClose(s2,0,0);

if((cl1>up1 && cl2<dn2 && op1<up1 && op2>dn2) || (cl1<dn1 && cl2>up2 && op1>dn1 && op2<up2)) Alert(s1+" + "+s2+" Signal!!!");
  // if((cl1<dn1 && cl2>up2 && op1>dn1 && op2<up2)) Alert(s1+" "+s2+" Signal!!!");

   Comment("\n UP1: ",up1,
           "\n DN1: ",dn1,
           "\n OP1: ",op1,
           "\n CL1: ",cl1,
           "\n ",
           "\n UP2: ",up2,
           "\n DN2: ",dn2,
           "\n OP2: ",op2,
           "\n CL2: ",cl2);
//--- return value of prev_calculated for next call
   return(rates_total);
  }
//+------------------------------------------------------------------+

Если цена пересекла противоположные границы индикатора на двух парах одновременно, должен воспроизвестись один раз звуковой алерт с указанием пар,