Boot-up message
After the initialization phase and the self-test the device sends the boot-up message, which is a CAN message with a data byte (0) on the identifier of the guarding or heartbeat message:
CAN-ID = 0x700 + node ID.
In this way temporary failure of a module during operation (e.g. due to a voltage interruption), or a module that is switched on at a later stage, can be reliably detected, even without Node Guarding. The sender can be determined from the message identifier (see default identifier allocation).
It is also possible, with the aid of the boot-up message, to recognize the nodes present in the network at start-up with a simple CAN monitor, without having to make write access to the bus (such as a scan of the network by reading out parameter 0x1000).
Finally, the boot-up message communicates the end of the initialization phase. The device indicates that it can now be configured or started.
Format of the Boot-up message
11 bit identifier | 2 byte of user data | |||||||
|---|---|---|---|---|---|---|---|---|
0x700 (=1792)+ node ID | 0x00 |
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