Two Safety Integrated managers lead the group; John Cusimano manages the process industries segment from Siemens’ Spring House, Pa., location while J.B. Titus manages the discrete industries segment from the company’s Norcross, Ga., facility.
Says Cusimano, “The market demands integrated products for safety applications.” At the same time, he continues, changes in safety regulations offer users a choice beyond the traditional hardwired safety stop requirements. “Programmable controllers that are certified by Nationally Recognized Testing Laboratories (NRTLs), such as FM (Factory Mutual), UL (Underwriters Laboratory) and TUV, can be used to automate machine safety interlocks to the highest category SIL (safety integrity level).”
Siemens’ Simatic S7 Safety Integrated programmable logic controllers (PLCs) have received a UL 508 Listing, which covers control equipment that incorporates software, for functional safety. Says Titus, “Safety Integrated technology is incorporated into Siemens Totally Integrated Automation (TIA) to provide a broad range of safety certified products.” In addition to PLCs, these include sensors, industrial control products, motion control products and drives.
In the past, safety products needed to be on a separate network from the standard PLC network. Changes in regulations now allow safety and control PLCs to exist on the same safety certified network, which saves time and commissioning costs. For safety, Siemens offers Profisafe, which complies with safety standard IEC 61508, and is layered on top of standard Profibus DP protocol, using existing communication components, such as cables, circuit chips and software. Possible errors are countered with four measures to check for corruption, delay, authenticity and security.
Siemens representatives cite an automotive original equipment manufacturer that used Safety Integrated and TIA products to realize a 44 percent savings in wiring, product, engineering and installation costs.