Change Channel During RunTime

Ryan, the command works like a charm.

Ryan Brown1Do you have any reason why we cannot manipulate _NIB in NV for current CC26xx Z-Stack to change channel like what we used to do in CC253x Z-Stack?

Hi YiKai,

I have not investigated whether it is possible to directly modify the NV NIB's for Zigbee channel after a node has joined or formed a network.  However, doing so silently would disrupt connections between other nodes within a network since they have not been made aware of the channel change.  It is recommend that the network manager layer oversees channel changes and notifies other nodes in the network before switching.  Otherwise it should simply factory reset to create or join a different network on the new channel.

Regards,
Ryan

Ryan Brown1 Yes, I know the consequences to revise NIB to change channel and I just use it for testing sleeping end device which will scan channel anyway. I just want to know why CC253x Z-Stack works bot not CC26xx Z-Stack. If you know exact reason, please let me know.

ZDO_MGMT_NWK_UPDATE_REQ appears capable of revising the NIB to change channels, although some other APIs (NLME_SetUpdateID, ZMacSetReq, ZDApp_NwkStateUpdateCB) may also be required to achieve your desired functionality.

//zd_nwk_mgr.c

  if ( events & ZDNWKMGR_CHANNEL_CHANGE_EVT )
  {
    // Switch channel
    _NIB.nwkLogicalChannel = ZDNwkMgr_NewChannel;
    ZMacSetReq( ZMacChannel, &ZDNwkMgr_NewChannel );

    // Our Channel has been changed -- notify to save info into NV
    ZDApp_NwkStateUpdateCB();

    // Reset the total transmit count and the transmit failure counters
    _NIB.nwkTotalTransmissions = 0;
    nwkTransmissionFailures( TRUE );

    return ( events ^ ZDNWKMGR_CHANNEL_CHANGE_EVT );
  }
  
//...
  else if ( Req.scanDuration == 0xFE )
  {
    // Request is to change Channel. The command provide a new active
    // channel as a single channel in the channelMask.
    // Only process when the nwkUpdateId is more recent (accounting for uint8 wraparound)
    if ( Req.nwkUpdateId > _NIB.nwkUpdateId || ( Req.nwkUpdateId == 0 && _NIB.nwkUpdateId == 0xFF ) )
    {
      uint8_t i;

      // Set update ID in the Beacon
      NLME_SetUpdateID(Req.nwkUpdateId);

      // Find out the new active channel
      for ( i = 0; i < ED_SCAN_MAXCHANNELS; i++ )
      {
        if ( ( (uint32_t)1 << i ) & Req.channelMask )
        {
          break;
        }
      }

      if ( _NIB.nwkLogicalChannel != i )
      {
        ZDNwkMgr_NewChannel = i;

        // Upon receipt of a Mgmt_NWK_Update_req with a change of channels,
        // the local network manager shall set a timer equal to the
        // nwkNetworkBroadcastDeliveryTime and shall switch channels upon
        // expiration of this timer.  Each node shall also increment the
        // nwkUpdateId parameter and also reset the total transmit count
        // and the transmit failure counters.
        OsalPortTimers_startTimer( ZDNwkMgr_TaskID, ZDNWKMGR_CHANNEL_CHANGE_EVT,
                            ZDNWKMGR_BCAST_DELIVERY_TIME );
      }
    }
  }

Regards,
Ryan

Ryan Brown1my question is why we cannot write NV ID of _NIB to revise channel information now in CC26xx Z-stack which used to work in CC2530 Z-stack?

Hi YK,

I can replicate this behavior and believe it is associated with the osal NV driver write operations and read functionality which have changed since legacy CC253X Z-Stack 3.0.2, please allow more time for me to further investigate.

Regards,
Ryan

Ryan Brown1Thanks for investigating into this and looking forward to getting answer from you.

Apologies as this message appears to have been left unposted...

I have noticed that after writing a single byte to the ZCD_NV_NIB, SYS_OSAL_NV_READ -> MT_SysOsalNVRead -> osal_nv_read -> osal_nv_read_ex -> readItem -> NVOCMP_readItemApi -> NVOCMP_readItem -> NVOCMP_verifyCRC returns NVINTF_CORRUPT. It appears that MT_SYS_OSAL_NV_WRITE -> MT_SysOsalNVWrite -> osal_nv_write does not appear to consider the offset any longer, thus the incorrect bytes could be written which causes the corruption error which returns a blank NV read.

Regards,
Ryan

Ryan Brown1Will you fire a TI internal bug ticket to fix this in the future?

Thanks, Ryan Brown1