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After the gateway connects to ClearBlade IoT Core over the MQTT bridge, it can send or receive three message types of messages:
Control messages: Attaches a device to the gateway or detaches a device from the gateway. These messages are sent between the gateway and ClearBlade IoT Core. ClearBlade IoT Core accepts control messages only from gateways; if another type of device attempts to send a control message, ClearBlade IoT Core closes the connection.
Messages from gateways and devices: Can be relayed by the gateway on a device’s behalf or sent directly from the gateway.
System error messages: When the gateway is subscribed to the MQTT system error topic on the device’s behalf, ClearBlade IoT Core sends error messages whenever the device encounters an error.
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