Making equipment safe for operators has always been a difficult task, but it’s becoming much easier. PC-based controllers can now be used to program safety features and functions, eliminating much of the complexity associated with segregated safety systems and buses.

Siemens has unveiled what it says is the first PC-based software controller, the SIMATIC WinAC RTX F. Expanding the SIMATIC line to include safety simplifies the task of engineers who want to meet the most demanding safety integrity level standards.

“This meets SIL 3, Category 4, which is the highest level of safety," says Tim Parmer, Automation Consultant, Safety, for Siemens. It also complies with EN 954-1 to Cat. 4, IEC 62061 and EN ISO 13849-1 to PL e.

There are a number of benefits to eliminating the hardwired safety connections of prior generations. Among them is that programmers can write safety-related software that can be more closely integrated with the code used to control the equipment’s main features and functions. In the system, the modifications to the standard programs have no effect on the safety functions or the revision signatures of the safety-relevant software. Programmers can now write code in the PLC, using the same tools and methodologies used for standard ladder logic software.

Sending safety signals over the same network as other data also helps trim costs while eliminating the need for dedicated safety buses. “Communications are tremendously better, wiring is simpler and documentation is better," Parmer says. “There’s also a substantial reduction in the cost of engineering, operating and maintaining the machine. A few hundred dollars gets you into PC-based safety; you simply add the safety functionality to the PC of your choice.”

The runtime system used by SIMATIC WinAC RTX F is optimized to handle extensive PC applications in parallel with the control task while meeting strict real-time requirements. It can utilize dual core processors to achieve high throughput, for example, dedicating one core for Windows applications and another core for SIMATIC WinAC RTX F.

The ODK (Open Development Kit) provides optimal access to controller runtime data. The controller line can be expanded with distributed safety I/O modules of the ET 200S, ET 200M, ET 200pro (IP67) or the safety block I/O ET 200eco (IP67).

SIMATIC WinAC RTX F is a safety S7 software controller for Windows XP-based PCs that can be installed on all current x86 hardware platforms. That includes all SIMATIC PCs.
For more information on the SIMATIC WinAC RTX F, please click here.