Class A Downlink

I am trying to send a downlink payload to my device. When I enqueue a message and refresh, the queue empties right away. I expect it to wait for my uplink but that does not happen. I enqueued a bunch of downlink payloads and one just happened to fall into the rx window and it got sent. Please help me with this issue. Is there a setting I am missing? Thank you.

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if your endnode is really Class A, disable all other classes support in the device profile

I do have Class B and Class C disabled (boxes unchecked) in device profile.

Another thing I am experiencing is my device sends an uplink every 10s, but the Device Data section sometimes get about 4 consecutive uplinks, but sometimes it misses a bunch and receives one after a minute (it skips frames).

This is too frequent, approx. 8.5K messages/day per LoRaWAN node

It depends on many factors (payload size, datarate, number of endnodes etc.)

Golden rule: 30 seconds air-time per device per day
For 10 bytes of payload, this translates in (approx.):
    20 messages per day at SF12
    500 messages per day at SF7
    more for SF7BW250 and FSK (local-area)
If your application requires more bandwidth, think of another solution
This allows for >1000 nodes per gateway
Downlink bandwidth is even more restricted
    you can’t send all messages as ‘confirmed uplink’

I am still missing uplinks. I discovered the channels I had configured on my Gateway was 8-15,65, but in the network-server.toml I had 1-7,64. I fixed that error, but the same result. Don’t know why it was getting any uplinks in the first place. Can you help me with what I should configure in the “Gateway-profiles” page. There are options like “Enabled channels” then “Extra channel 1” I have no idea if I have those configured correctly. There were no documents I found only a video (

Thank you.

Also still have the issue with downlink where the queue does not wait for the next uplink, but sends the downlink as soon as it is queued.

reduce the frequent sending the uplink and you will see that downlink is in queue and sends after each endnode uplink

I am also facing the exact issue. My uplink frequency is every 20 minutes, when I schedule a downlink it should wait for the uplink but the queue empties right away.

@brocaar Please help!
@pjay Were you able to solve it ?

Hi guys, I’m having a problem. When sending commands by MQTT, my commands are queued and not sent to the device.

It sounds like you have configured your device as Class-C in the device-profile. In which case ChirpStack assumes the device is always listening and thus it will send the downlink immediately instead of waiting for the next uplink.

Please check the configuration in below images.

I have the same problem as Rajib, although the device is configured neither as Class-B nor as Class-B, the uplink is sent immediatelly as I enqueue the payload in base64. The device is a water meter, BMeter LR-1.

Thank you for any advice,