Type 3: Communication error
Communication errors happen when messages cannot be delivered or timeouts occur. The recipient of the message is either unknown or busy.
These error messages contain the following additional diagnostic data:
Data format | Element | Contains |
UNS16 | Medium | Communication medium |
UNS16 | Typ | PDU code or function block type |
UNS32 | Partner | Sender |
Practical examples:
- Invalid PDU code received
- Channel block marked as 'not processed'
- Incorrect content of a PDU block