Siemens Industry, Inc. (www.siemens.com) has broadened its SIMATIC ET 200iSP I/O system with the addition of three new modules to conform to safety standards ISO 13849-1 up to PLe e or IEC 61508 up to SIL 3. A modular I/O system suitable for hazardous areas, the ET 200iSP features actuators and sensors directly connected to a bus system, while its I/O system can be fitted in a non-explosion roof cabinet.

With modules ideally suited for various applications including boiler protection, emergency shutdown as well as fire and gas equipment, the ET 200iSP’s isolating transformer is a bus isolating transformer that creates an intrinsically safe PROFIBUS DP communications network.

The terminal modules of the I/O system are plugged with PROFIBUS DP interface modules, function modules — which include an explosion proof power supply — and a maximum of 32 electronics modules. The ability of the I/O system to “Hot Swap” the electronic module enables customers to avoid costly downtime when stopping the controller. The PROFIBUS DP interface module’s firmware can be upgraded over PROFIBUS DP or using a micro memory card (MMC).

Maximum uptime is available with PROFIBUS DP, while redundant power supplies allow for redundancy. When utilized in a redundant configuration, the I/O system’s power supplies can be replaced and hot swapped under power even in highly hazardous locations.

With an analog signal of four to 20 mA, the ET 200iSP links process devices with Highway Addressable Remote Transducer (HART) technology. A routing function within the PROFIBUS DP allows a central station to transparently access HART process devices. Thus, more process instruments, including fill-level, temperature, flow rate measuring equipment and pressure, can be configured and accessed.