PROFIsafe was the first communication standard in compliance with IEC 61508, which permits standard and safety-related communications on one and the same bus. With SIL 3 (Safety Integrity Level), it fulfills the highest requirements in the process industries.

PROFIsafe utilizes the standard services of the lower-level bus system to implement safe communication. When transmitting messages, PROFIsafe comes up with four measures against any possible faults or errors such as corrupted addresses, loss, delay, etc.:

	PROFIsafe is consecutively numbered
	The time is monitored (watchdog)
	Authenticity is monitored using "passwords"
	An optimized CRC (Cyclic Redundancy Check) detects corrupted data bits in a message frame

PROFIsafe uses existing standard communication components such as
cables, ASICs and standard software packages.

Your benefits with the PROFIsafe profile:
	Flexible Modular Redundancy - ultimate flexibility to choose the redundancy levels to fit the Safety Instrumented Function
	Reduced inventory thanks to savings on components - just one PROFIBUS cable for standard and safety-related communication is possible
	Faster system setup and commissioning - use of existing PROFIBUS cable for fail-safe communication too
	Increased flexibility - safety and standard automation can be separated on two different PROFIBUS cables