This compares a CAN-based safety layer (CANopen Safety / SRDO) with an Industrial-Ethernet safety layer (PROFIsafe over PROFINET). Both are IEC 61784-3 black-channel profiles certifiable to SIL 3 / PL e, but they live in different worlds: CANopen Safety in compact and mobile CAN networks, PROFIsafe in factory automation and Siemens ecosystems.
At a glance
| Criterion | CANopen Safety | PROFIsafe |
|---|---|---|
| Transport | Classical CAN, ≤1 Mbit/s | PROFINET (or PROFIBUS) |
| Standard | EN 50325-5 / CiA 304 | IEC 61784-3-3 |
| Max integrity | SIL 3 | SIL 3 / PL e / Cat 4 |
| Safety frame | SRDO dual inverted frames + CRC + SRVT | F-PDU: F-Data, control, consecutive number, CRC |
| Addressing protection | COB-ID + inverted redundancy | Virtual F-Address folded into CRC seed |
| Typical safety cycle | ~10–50 ms | 4–32 ms |
| Master model | No master (broadcast) | F-Host ↔ F-Device |
| Typical domains | Mobile machinery, off-highway, elevators | Factory automation, process, Siemens plants |
Engineering detail
CANopen Safety adds no special hardware — SRDOs run on the same CAN controller as standard CANopen — making it attractive for cost- and space-constrained mobile safety. PROFIsafe layers F-PDUs inside ordinary PROFINET I/O frames; a clever design point is the virtual F-Address, which is not transmitted but folded into the CRC seed, so a misrouted frame fails CRC at the wrong device. PROFIsafe uses a consecutive number plus watchdog for sequence and delay/loss detection and defines the Safety Function Response Time (SFRT).
PROFIsafe additionally requires PI certification of the F-Device on top of PROFINET, and is positively assessed by IFA and TÜV.
When to choose which
CANopen Safety for distributed, cost-sensitive safety on CAN in vehicles and machines. PROFIsafe when the machine is on PROFINET, especially in Siemens/TIA environments where the F-Host is a Siemens F-CPU.
The ISIT-Neperis stacks
ISIT-Neperis’s CANopen Safety stack (EN 50325-5) is available pre-certified to SIL 3, delivered with the certification artefact pack — the fast path to safe CAN devices without a separate safety bus.