docs: function _handleMEI(requestBuffer, vector, unitID, callback) {
      var MEIType = requestBuffer[2];
      switch(parseInt(MEIType)) {
          case 14:
              _handleReadDeviceIdentification(requestBuffer, vector, unitID, callback);
              break;
          default:
              callback({ modbusErrorCode: 0x01 }); // illegal MEI type
      }
  }