Can someone tell me why sometimes Rx1 Delay responses show up and sometimes they don’t?..Is this a TTN glitch or is it my firmware? I have read somewhere on line of the issue and it could be a timing issue with the gateway (Seeed WM1302 on RPI 3b+)…if gateway is there something I can do?
Thanks
Does your firmware ACK the MAC command issued to the node? Because you shouldn’t be seeing repeated instances at all if you have a LoRaWAN compliant stack on a node that receives downlinks.
i would reduce the rssi as well as to reduce possible future issues
and as mentioned in the post above
They are not repeated instances…(sorry didn’t show timestamp). It is just sometimes I get “Successfully proecessed data…” after a “Forward uplink data message” and somtimes I get “Schedule data downlink…”
The “Schedule data …” message is occurring without me scheduling anything.
The RX1 Delay messages are generated by the TTN Stack to instruct your node to modify a certain setting. LoRaWAN uses MAC commands for this purpose. Those commands require an acknowledgement in the next uplink packet so the TTN Stack knows the MAC command has been successfully processed.
If your node does not receive the downlink it will not acknowledge the command. Neither will it if your LoRaWAN stack does not implement this (mandatory) MAC command.
Because the TTN stack does not get an acknowledgement it will repeat this downlink, wasting gateway airtime by having it transmitted (at which time a gateway can’t listen for uplinks) and consuming the radio waves. So make sure your node can receive the downlink and process it successfully.
**If your node does not receive the downlink it will not acknowledge the command. **
So “Successfully processed data…” (which is time stamped with the next transmission) is my node telling TTN it transacted that MAC command?
The message “Successfully…” and “Forward uplink data message” have the same timestamp. Can I presume that the MAC layer allows for both data and MAC response to be sent to TTN in the same message?
No, it means it successfully processed the data - your payload.
That means your payload was passed along the conveyor via the payload formatter.
There is a detailed spec to LoRaWAN that answers such things definitively so no need to presume - per previous topics, please read the Learn section if you’ve not already done so as an intro to the MAC commands are covered there in the Message Types section.
But as it happens, yes, it is possible to send some MAC commands / acks back up with your payload.
But this is clearly not happening otherwise the LNS wouldn’t schedule a Rx1 Delay message to downlink.
No, TTN is telling you it received data and passes it along to the next step.
Given the repeated transmission your node does not process and acknowledge the MAC command. Which I stated already in the last paragraph of my previous reply.
