Glossary · Data, timing and communication
openSAFETY
Also known as: open safety
German: openSAFETY
In industrial communication, openSAFETY is an open, fieldbus-independent safety protocol for transmitting safety-related data over standard networks according to the black channel principle. It is specified as a functional safety communication profile in IEC 61784-3.
- Functional safety
- Data and interfaces
In one sentence
openSAFETY is an open, fieldbus-independent safety protocol that transmits safety data over standard networks using the black channel principle.
Example
A packaging line transmits emergency stop and guard door signals from remote I/O to a safety controller via openSAFETY over the same POWERLINK network that carries the standard process data.
How it applies
- Engineering: openSAFETY was originally developed by B&R and is maintained by the Ethernet POWERLINK Standardization Group. It is designed to run over different transport networks.
- Black channel: Safety measures such as sequence numbers, time expectations, identifiers and checksums sit in the safety layer, so the underlying network does not need to be safety-rated.
- Timing: Watchdog times and the resulting reaction time are part of the safety calculation and of Protective response time and safe distance evaluations.
- Documentation: Document the safety addresses, watchdog times and the network configuration. The documentation team should state that the protocol provides a safety-rated communication channel, not a safe machine; the safety functions still need their own verification.
openSAFETY vs. PROFIsafe
Both are safety profiles listed in IEC 61784-3 and use the black channel principle. PROFIsafe is tied to PROFIBUS and PROFINET, while openSAFETY is designed to be independent of the underlying fieldbus.