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IoT Platform:Operational logs

Last Updated:Jun 22, 2026

After you run the MQTT 5.0 connection sample, view logs on the device and in IoT Platform to verify connectivity.

Prerequisites

The MQTT 5.0 connection sample for the C Link software development kit (SDK) is configured and running. For more information, see Use the sample.

Device-side logs

View the running results on the device.

  1. Connection logs.

    The following logs indicate that the device is successfully connected to IoT Platform.

    [1680608104.988][LK-0313] MQTT user calls aiot_mqtt_connect api, connect
    [1680608104.988][LK-032A] mqtt host: a18wP******.iot-as-mqtt.cn-shanghai.aliyuncs.com
    [1680608104.988][LK-0317] user name: LightSwitch&a18wP*******
    [1680608104.988][LK-0318] password: 4CEB5BA5B334CDB73DAAEEF97EBC1A09*******************
    success to establish tcp, fd=3
    local port: 34624
    [1680608104.999][LK-1000] establish mbedtls connection with server(host='a18wP*******.iot-as-mqtt.cn-shanghai.aliyuncs.com', port=[1883])
    [1680608105.066][LK-1000] success to establish mbedtls connection, (cost 45329 bytes in total, max used 48297 bytes)
    [1680608105.099][LK-0000] MQTT_PROP_ID_RECEIVE_MAXIMUM:10 
    [1680608105.099][LK-0000] MQTT_PROP_ID_TOPIC_ALIAS_MAXIMUM:20 
    [1680608105.099][LK-0000] MQTT_PROP_ID_MAXIMUM_QOS:1 
    [1680608105.099][LK-0000] MQTT_PROP_ID_RETAIN_AVAILABLE:1 
    [1680608105.099][LK-0000] MQTT_PROP_ID_MAXIMUM_PACKET_SIZE:262144 
    [1680608105.099][LK-0000] MQTT_PROP_ID_WILDCARD_SUBSCRIPTION_AVAILABLE:1 
    [1680608105.099][LK-0000] MQTT_PROP_ID_SUBSCRIPTION_IDENTIFIERS_AVAILABLE:0 
    [1680608105.099][LK-0000] MQTT_PROP_ID_SHARED_SUBSCRIPTION_AVAILABLE:1 
    [1680608105.099][LK-0000] MQTT_PROP_ID_SESSION_EXPIRY_INTERVAL:0 
    [1680608105.099][LK-0000] MQTT_PROP_ID_SERVER_KEEP_ALIVE:1200 
    [1680608105.099][LK-0313] MQTT connect success in 116 ms
  2. You can subscribe to topic logs.

    [1680608105.099][LK-0309] sub: /sys/a18wP******/LightSwitch/thing/event/property/post_reply
  3. Message reporting logs.

    [1680608105.099][LK-0309] pub: /sys/a18wP******/LightSwitch/thing/event/property/post
    
    [LK-030A] > 7B 22 69 64 22 3A 22 31  22 2C 22 76 65 72 73 69 | {"id":"1","versi
    [LK-030A] > 6F 6E 22 3A 22 31 2E 30  22 2C 22 70 61 72 61 6D | on":"1.0","param
    [LK-030A] > 73 22 3A 7B 22 4C 69 67  68 74 53 77 69 74 63 68 | s":{"LightSwitch
    [LK-030A] > 22 3A 30 7D 7D   

IoT Platform logs

View the device status and operational logs in the IoT Platform console.

  • Online status:

    In the navigation pane on the left, choose Device Management > Devices. Find the device and view its status. If the device status is Online, the device is connected to IoT Platform.

  • Operational logs:

    In the navigation pane on the left, choose Monitoring and O&M > Simple Log Service. Select a product, and then view the logs for device online events, topic subscriptions, and message reporting.

What to do next

If an error message appears in the operational logs, see Common error codes to resolve the issue.