Frame logging

ChirpStack Application Server makes it possible to log frames sent and received by a gateway or device in realtime. To use this feature, you first need to go to the gateway or device detail page. Once you are on this page, open the LoRaWAN frames tab.

Note: This is a feature for debugging the communication between the network-server and your devices. Do not use this for integration with your applications.

As soon as you open this page, ChirpStack Application Server will subscribe to the frames sent / received by the selected gateway or device. Once a frame is sent or received, it will be displayed without the need to refresh the page.

Gateway frame logs

The frame logs view on the gateway detail page will display all frames sent and received by the selected gateway.

Device frame logs

The frame logs view on the device detail page will display only the frames that could be related to a device. This means that in case you want to debug MIC issues, this view might not show this information and it is better to use the gateway view.

Exposed information

Note that all the displayed data can be expanded by clicking on each key. E.g. > phyPayload: {} 3 keys means you can expand this phyPayload item as it has three sub-items. This makes it possible to inspect (unless encrypted):

• TX related meta-data (frequency, data-rate, ...)
• RX related-meta-data (RSSI, SNR, timestamps, ...)
• LoRaWAN PHYPayload frames and mac-commands (unless encrypted)

Storing frames

Frames displayed are not stored in a database. As soon as you refresh the page, all data is gone. If you need to store these frames, you can use the download button which will generate a JSON formatted file containing all the frames that are logged since opening the Live frame logs tab.

Example JSON output

[
    {
        "uplinkMetaData": {
            "rxInfo": [
                {
                    "mac": "0102030405060708",
                    "time": "2018-02-13T14:00:00.683952Z",
                    "timeSinceGPSEpoch": "",
                    "timestamp": 123456,
                    "rssi": -150,
                    "loRaSNR": -7,
                    "board": 0,
                    "antenna": 0
                }
            ],
            "txInfo": {
                "frequency": 868300000,
                "dataRate": {
                    "modulation": "LORA",
                    "bandwidth": 125,
                    "spreadFactor": 12,
                    "bitrate": 0
                },
                "codeRate": "4/5"
            }
        },
        "phyPayload": {
            "mhdr": {
                "mType": "UnconfirmedDataUp",
                "major": "LoRaWANR1"
            },
            "macPayload": {
                "fhdr": {
                    "devAddr": "01020304",
                    "fCtrl": {
                        "adr": false,
                        "adrAckReq": false,
                        "ack": false,
                        "fPending": false
                    },
                    "fCnt": 1234,
                    "fOpts": null
                },
                "fPort": 1,
                "frmPayload": [
                    {
                        "bytes": "..."
                    }
                ]
            },
            "mic": "04030201"
        }
    }
]