code: function _readFC2(data, next) {
      var length = data.readUInt8(2);
      var contents = [];
  
      for (var i = 0; i < length; i++) {
          var reg = data[i + 3];
  
          for (var j = 0; j < 8; j++) {
              contents.push((reg & 1) === 1);
              reg = reg >> 1;
          }
      }
  
      if (next)
          next(null, { "data": contents, "buffer": data.slice(3, 3 + length) });
  }
docs: @fileoverview ModbusRTU module, exports the ModbusRTU class.
  this class makes ModbusRTU calls fun and easy.
  
  Modbus is a serial communications protocol, first used in 1979.
  Modbus is simple and robust, openly published, royalty-free and
  easy to deploy and maintain.
   
  Parse the data for a Modbus -
  Read Coils (FC=02, 01)
  
  @param {Buffer} data the data buffer to parse.
  @param {Function} next the function to call next.