Glossary · Industrial communication
Telegram
Also known as: Message, Frame (fieldbus)
German: Telegramm
In industrial communication, a telegram is a message with a defined structure that is transmitted as a unit between devices, consisting of addressing, control information, user data and a checksum. The term is common in fieldbus and drive documentation, especially in translations from German.
- Industrial communication
- Technical documentation
In one sentence
A telegram is a structured message transmitted as a unit between devices, with address, control data, user data and checksum.
Example
The drive's PROFIdrive standard telegram 1 contains a control word and a speed setpoint from the PLC, and a status word and actual speed back.
How it applies
- Engineering: In drive technology, "telegram" often refers to a predefined process data layout (for example PROFIdrive standard telegrams), which fixes which words are exchanged in which order.
- Commissioning: The telegram type configured in the controller must match the drive setting; a mismatch leads to wrong or missing data.
- Diagnostics: Error counters for lost or faulty telegrams point to communication problems.
- Documentation: The documentation team decides whether to use "telegram", "frame" or "message" and applies it consistently; English readers outside drive technology may find "telegram" unfamiliar, so a glossary entry and a first-mention explanation help. Telegram layouts should be documented word by word and bit by bit.
Telegram vs. frame
In practice they often mean the same transmitted unit. "Frame" is the standard term for the data link layer unit in Ethernet documents; "telegram" is common in fieldbus and drive documents and may refer to the application-level structure of the payload.