Glossary · Data, timing and communication
PROFIsafe
German: PROFIsafe
In industrial communication, PROFIsafe is the functional safety communication profile for PROFIBUS and PROFINET, specified in IEC 61784-3. It transmits safety-related data between safety controllers and safety devices over the standard network according to the black channel principle.
- Functional safety
- Data and interfaces
In one sentence
PROFIsafe is the safety communication profile for PROFIBUS and PROFINET that sends safety data over the standard network as a black channel.
Example
A safety PLC receives the emergency stop signals of several operator panels and sends Safe Torque Off commands to drives via PROFIsafe over the same PROFINET network used for standard control.
How it applies
- Engineering: PROFIsafe is maintained by PROFIBUS & PROFINET International. Safety devices and controllers exchange PROFIsafe messages that include measures such as a consecutive number, a watchdog time, a unique address relation and a CRC.
- Black channel: Because the safety measures sit in the profile, standard network components can carry the safety data, but the configured watchdog time adds to the reaction time of every safety function using it.
- Commissioning: Each device needs its correct PROFIsafe address, which must be unique in the relevant network. Addressing errors are a typical commissioning issue.
- Documentation: Document PROFIsafe addresses, watchdog times and the resulting reaction times. The documentation team should keep the device replacement procedure clear, since a replaced device must receive the correct address before the safety function is restored.
PROFIsafe vs. PROFINET
Protocol (communication) terms are easily mixed up here. PROFINET is the industrial Ethernet network; PROFIsafe is the safety layer on top of it. A PROFINET network is not safety-rated in itself.