Communication

PROFIsafe profile

PROFIsafe is a profile for PROFIBUS and PROFINET certified according to IEC 61508. With SIL 3 (Safety Integrity Level) or Category 4 according to EN 954-1, PROFIsafe fulfills the highest safety requirements of the process and manufacturing industry. Both safety-oriented and standard communication are possible via one and the same cable.

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.:

• Consecutively numbered PROFIsafe data
• Time monitoring (watchdog)
• An identifier between transmitter and receiver, for example, over unique PROFIsafe addresses
• An optimized CRC (Cyclic Redundancy Check) to detect corrupted data bits in a message frame

In combination with the user program of the F-CPU, the plant is put into a safe state and is kept in this safe state if any communication error occurs.

This type of single-channel, Safety communication based on the "Black Channel" system has already proven its worth to date in thousends of PROFIBUS-based automation solutions. By porting the PROFIsafe profile to PROFINET, this "safety profile" is now also available for safety-oriented wireless communication by using the standard transmitting modules SCALANCE W. Now, fragite mechanical data couplers can be substitute easier and with less attendance costs. Also the avaibility will incrase compared with the mechanical solutions.