InTech

MAY-JUN 2017

Issue link: http://intechdigitalxp.isa.org/i/833037

Contents of this Issue

Navigation

Page 12 of 53

COVER STORY INTECH MAY/JUNE 2017 13 rameters. The applied explosion protec- tion shall be internationally recognized. EMC Devices and components will conform to the NE 21 electromagnetic compat- ibility (EMC) requirements. Binary signals Simple interface modules, preferably compact two-wire devices or modular mini-I/Os, shall be provided for binary signals, such as switches, initiators, sole- noid valves, and signal lamps. As a rule, direct bus connection shall be possible. Safety instrumented systems A special protocol version for safety appli- cations shall be available and transmitted via the same medium as normal protocols ("black channel" principle). An adequate number of safety-oriented field devices and controls must be available. As in the case of conventional safety instrumented systems, the sensor/actuator systems of the field devices and the bus coupling of the field device signal shall be proven in use or at least meet safety integrity level 2 requirements. This ensures adequate re - duction of systematic errors without, how- ever, being explicitly certified. To ensure safe data transmission, protocol stacks in accordance with IEC 61508 are used in the sensors and actuators that put the reliably generated signals on the bus. The protocol that ensures safety (safety layers in addition to transmission layers) can be selectively activated by a switch in the field device. This means that the devices can be used for both safety-related and non - safety-related equipment. These devices shall be commissioned in the same way as standard devices. A hardware switch to lock parameterization is required. Field device integration (NE 105) The device packages required for field de- vice integration shall be available in the devices and capable of being transmitted to central tools following NE 105 Specifi- cations for Integrating Fieldbus Devices in Engineering Tools for Field Devices. Transmission of measuring values Measuring and control values shall be transmitted without a configuration file. To this end, it is necessary to agree on defined profiles, such as AI, AO, DI, and DO. Configuration Parameterizing, configuring fieldbus devices, signal flooding, and connect- ing additional devices must not inter- fere with the transmission of measur- ing data and shall be possible during ongoing operation. Automatic addressing Devices and components shall be ad- dressed automatically. It shall be possi- ble to activate entire segments or areas.

Articles in this issue

Links on this page

Archives of this issue

view archives of InTech - MAY-JUN 2017