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CC1310: TI15.4 Beacon MODE, some times sensor will loss 4 beacons and sync again

Part Number: CC1310

I have a problem that with TI15.4 STACK, Beacon MODE, some times sensor will loss 4 beacons. But I checked the RSSI signal, it is good!

I route out LNA active pin to gpio.  And  I find that in sensor side, the beacon receive windown is about 10.4ms。

As I add some data to COP beacon payload, now the length of beacon is 85 bytes (confirmed by sniffer). The rate is  50kbps.

so it need  (85*8)/(50*1024) = 13.28125ms  to  send the bytes.

But in the sensor side ,it only have 10.4ms beacon receive window, Is it the problem??

So, How can I modify the beacon recieve windows on sensor side? 

Here is the relate setting of my project:

#define CONFIG_MAC_BEACON_ORDER          4  


#define CONFIG_RX_ON_IDLE          false

Many thanks!


  • Hi Jun,

    A few questions before I can help you.

    1. Which version of the SDK are you using?

    2. When you say that you loss four beacons, do you mean that the sensor only receives one out of every four beacons, or that sometimes the sensor does not detect the beacons?

    3. What do you mean when you mention that the RSSI signal is good?

    4. Have you used a packet sniffer to see if the Beacons are being sent from the collector? It would be important to identify if the problem is in the sensor or in the collector?

    5. Are the settings for your project the same in both the sensor and the collector projects?


  • Thanks AndresM.

    1. simplelink_cc13x0_sdk_4_10_02_04

    2. sometimes the sensor does not detect the beacons, as  #define JDLLC_MAX_LOST_BEACONS  4 ,

         so after 4 beacon loss ,it will enter syncLossCb in jdllc.c

    3.  I have check the RF signal strength, I am sure the RSSI signal is enough. 

    4.  Yes, I have a packet sniffer, I confirm that the beacons are being sent from the collecotr. 

          Also I have other sensors to compare with. When  one sensor loss  beacon and blinking LED,  the others can get beacons normally.

    5.  the settings in config.h is the same in both sensor and collector projects.

    Thanks for your reply.



  • Hi Jun,

    Thank you for the answers.

    My first suggestion would be to first reduce the payload size to see if this has any effect on the behavior you are seeing.

    Afterwards we can check to see if there are more appropriate values for the beacon order and for the super frame order.

    Just out of curiosity, how many additional sensors do you have in your setup?


  • Thanks AndresM.

    1. Yes ,I will try your suggestion :reduce the payload size.  But my project need the enough length of payload.

    2. The beacon order and superframe order will effect the response speed of the beacon system. I will try,but 4 maybe the best for me.

    3. The sensors are about 20~50 in my system.

    And I want to know that :  Can I modify the beacon recieve windows on sensor side?



  • Hi Jun,

    The main issue here is that according to the TI 15.4-Stack User's Guide, the beacon size cannot exceed 56 bytes, as this may lead to problems.

    I don't think that there is a direct way to modify the beacon receive window on the sensor's side, as many of this is configured during the association procedure, and modifying it would probably lead to some sync issues as well.

    You can refer to the User's Guide to see how some of these values are calculated.


  • Thanks AndresM.


    Acturally, the beacon payload size cannot exceed 52 bytes. Anyway, Thanks AndresM.



  • Hi AndresM,

    I decrease the length of beacon payload to 69 bytes and the RX beacon windows of sensor side is 7.9ms.

    85bytes --> 10.4ms,  so 16bytes is 2.5ms, That is the bit rate 50kbps.

    I think the RX beacon windows of sensor side is relate to the beacon payload length.

    Back to my problem, sometimes one of the sensors loss above 4 beacons.

    Is that the RF match things? I will try it.  The band is 433MHz in my project.