Device Command (ct: 0)
Received when a command is sent from the /IOTCONNECT™ portal. Ensure MQTT messages are acknowledged at QoS 1 level to avoid duplicate delivery.
Cloud to Device (C2D) messages are received by your device from /IOTCONNECT™. This includes device commands, OTA updates, module commands, and system notifications for template changes, device lifecycle, and heartbeat control.
Received when a command is sent from the /IOTCONNECT™ portal. Ensure MQTT messages are acknowledged at QoS 1 level to avoid duplicate delivery.
Received when a firmware update is pushed from the /IOTCONNECT™ portal. Device should download from urls, apply update, and send OTA acknowledgment.
Received when a module push is sent from the /IOTCONNECT™ portal. Contains downloadable module artifacts.
The platform sends system commands to request device actions like refreshing configuration, stopping communication, or controlling heartbeat. All have the format:
| ct | Command | Device Action |
|---|---|---|
| 101 | Refresh Attributes | Send mt:201 to get updated attributes |
| 102 | Refresh Settings/Twin | Send mt:202 to get updated settings |
| 103 | Refresh Edge Rule | Send mt:203 to get updated edge rules |
| 104 | Refresh Child Devices | Send mt:204 to get updated child list |
| 105 | Data Frequency Change | Update reporting frequency to new value in message |
| 106 | Device Deleted | Stop communication, release MQTT connection |
| 107 | Device Disabled | Stop communication, release MQTT connection |
| 108 | Device Released | Stop communication, release MQTT connection |
| 109 | Stop Operation | Stop all communication, release MQTT connection |
| 110 | Start Heartbeat | Begin sending heartbeat at specified frequency |
| 111 | Stop Heartbeat | Stop sending heartbeat messages |
| 112 | Start KVS Stream | Start sending video to Kinesis Video Stream |
| 113 | Stop KVS Stream | Stop sending video to Kinesis Video Stream |
Platform requests device to change telemetry reporting frequency.
Platform requests device to start sending heartbeat at specified frequency.
Format for system commands (101-104, 106-109, 111-113). Device must react based on ct value.
C2D messages arrive on the c2d subscribe topic from the Identity API. Always acknowledge MQTT messages at QoS 1 level to prevent duplicate delivery after reconnection. For commands 106-109, the device must immediately disconnect and NOT attempt reconnection.