Greg Davis

Important changes to forums and questions

All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.

8 years, 5 months ago.

"LINK DEAD" Indication

After some time the NAmote gives a "LINK DEAD" indication and appears to stop working.

======== DEBUG STARTED

B: INITFUNC v3 JOINING JOINED Net ID = 0 LED1 = 0 LED1 = 1 TXCOMPLETE LED1 = 0 LED1 = 1 TXCOMPLETE LED1 = 0 LED1 = 1 TXCOMPLETE LED1 = 0 LED1 = 1 TXCOMPLETE LED1 = 0 LED1 = 1 TXCOMPLETE LED1 = 0 LED1 = 1 . . . TXCOMPLETE LED1 = 0 LED1 = 1 TXCOMPLETE LED1 = 0 LED1 = 1 TXCOMPLETE LED1 = 0 LINK_DEAD LED1 = 1

Nothing else after this...

Has this "error" been seen before?

Question relating to:

Last updated: 02 Mar 2016
LMIC transmit example for NAmote-72 with GPS

It appears to be related to #define CHNL_HYBRID. I am operating with a gateway with a single SX1301 so it was my understanding that I should define CHNL_HYBRID in this configuration. If CHNL_HYBRID is not defined the mote recovers form "LINK DEAD" by re-JOINING.

posted by Greg Davis 24 Nov 2015

1 Answer

wayne roberts
8 years, 5 months ago.

LINK_DEAD means it failed to receive a response from a link check request. To keep it trying to rejoin, I had commented out an if block after nojoinframe: in processJoinAccept(). If you want quicker link checking, you can change LINK_CHECK_INIT from -12 to something closer to 0. When LMIC.adrAckReq > 0, the link check is requested.

Accepted Answer

How does one disable the rejoin process entirely? In many cases it may not be appropriate to give up on the link just because communication is not bi-directional?

posted by Dave Kjendal 25 Nov 2015