Sending a downlink message

1

I’m trying to send a raw (bytes) downlink message to a LoraWan class A device I purchased.
I checked the payload with the manufacturer and he says it should be correct. The payload message should change an interval setting on the device. Im trying to send it on Fport 3

I’m trying to send it the following way using the things network community:
Screenshot from 2021-06-03 11-05-08

Then my scheduled downlink message will appear like this in the live data:

{
  "name": "as.down.data.forward",
  "time": "2021-06-03T09:01:42.694330881Z",
  "identifiers": [
    {
      "device_ids": {
           "device_id": "xxxSecret",
        "application_ids": {
          "application_id": "xxx"
        }
      }
    },
    {
      "device_ids": {
    "device_id": "xxxSecret",
        "application_ids": {
          "application_id": "xxxx"
            }
      }
    }
  ],
  "data": {
    "@type": "type.googleapis.com/ttn.lorawan.v3.ApplicationDownlink",
    "f_port": 3,
    "frm_payload": "ABAAAQIxAAEC",
    "correlation_ids": [
      "as:downlink:01F78HPQWZMZD18EMY5DJ4JF1W",
       "rpc:/ttn.lorawan.v3.AppAs/DownlinkQueuePush:xxx
    ]
  },
  "correlation_ids": [
    "as:downlink:01F78HPQWZMZD18EMY5DJ4JF1W",
    "rpc:/ttn.lorawan.v3.AppAs/DownlinkQueuePush:xxx"
  ],
  "origin": "ip-10-100-15-149.eu-west-1.compute.internal",
  "context": {
    "tenant-id": "xxxx"
  },
   "visibility": {
    "rights": [
      "RIGHT_APPLICATION_TRAFFIC_READ",
      "RIGHT_APPLICATION_TRAFFIC_READ"
    ]
  },
  "authentication": {
    "type": "Bearer",
    "token_type": "AccessToken",
    "token_id": "xxx"
  },
  "remote_ip": "xxxx",
  "user_agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:88.0) Gecko/20100101 Firefox/88.0",
  "unique_id": "xxx"
}

Am I overseeing something simple / doing something wrong in TTN?

Thanks for your possible time and effort!

2

Just the bit about telling us what the problem is, assuming there is one???

Also, what is the device, there is usually some context to these sorts of questions if we know the device.

Also, if it’s a vendor purchased device that you setup from the device repository, does it have a payload formatter for downlinks?

3

Looks OK what you’re trying to do in the console.

Is it an ABP or OTAA device?

What LoRaWAN specification version does your device support?
Have you correctly configured this in the console for this device?
Did you select the correct frequency plan?

4

Thank you for your replies!

The problem is that the device is not responding to my settings instructions which I should have sent via downlink. The manufacturer told me the payload i’m trying to send is correct and the device should respond.

This is the related device.

The device is class A, OTAA.

I haven’t set a payload formatter for downlink since I’m sending a binary payload already. Should I set a payload formatter in this case?

@bertrik The device supports LoraWan 1.0.3. , I’ve just selected this in the end devices page. Since your suggestion but It seems to no avail.

All other functions from the device work. It sends it’s data twice per day and all is coming through neatly. It just seems like my downlink messages do not reach the end device correctly.

5

Has this device joined V3 or was it migrated from V2?

There are of course a lot of possible causes, one is wrong timing for RX windows. Another being that the device can’t receive the transmissions due to RF interference or something like it.

Does the device traffic page on TTN show a downlink directly after each uplink has been received?

6

@kersing it has been registered in V3, the gateway it connects to is still registered in v2. It is a TTIG gateway.

When I look in the new livedata page I do not see a downlink message directly. I see a new downlink message is being scheduled but nothing about the one that I have scheduled.
My downlink count does show a number.

Since my device is currently unaccessible by me I will try to read out the console again when it connects.

Do i need to set a payload formatter when I enter the payload like this (binary)?

7

LoRaWAN is not WiFi. Nodes do not connect to gateways, nodes connect to the network and gateways just forward data between the network and the node.

What are the uplink and downlink counters? Seeing a downlink being scheduled for each uplink indicates a potential issue with the LoRaWAN stack of the device.

No you don’t need one,

8

The up and downlink counters are not the same.
For 1 device currently they are:
Uplink 56 and downlink 24. I think this is because I’ve been trying to que them a lot.

Last night I tried to send the message to a node and the downlink counter went up by 3.
I’m now forwarding all messages to my server via the webhook so I hope I can get some more debug from there.

I’ll log my updates here.

9

So the number of uplinks and the number of downlinks are not identical, which is normal. The majority should be uplinks (you need to worry when both counters are identical).

This is very probably caused by downlink MAC commands to set or query network related parameters.