docs: function readReportCfg (permAddr, auxId, attr, callback) {
      var shepherd = this,
          realAddr = helper.parsePermAddr(permAddr),
          dev = shepherd.find(realAddr.clientName),
          path = auxId + '/' + attr,
          err = null;
  
      if (dev) {
          dev.discoverReq(path, function (err, rsp) {
              err = err || helper.rspStatusChk(rsp.status);
  
              if (err)
                  callback(err);
              else 
                  callback(null, rsp.data.attrs);
          });
      } else {
          callback(new Error('Device not found.'));
      }
  }