Existing intrinsically safe field instrumentation connects to the spurs of DART Fieldbus. DART Fieldbus can be applied like any other PROFIBUS PA infrastructure available today as DART only protects the trunk. This means:
PROFIBUS PA instrumentation in process plants can now be installed with long cable distances and intrinsic safety throughout. The components that make that happen are defined and described below.
The DART Power Hub and Segment Coupler 3 (SK3) is based on the popular FieldConnex High-density Power Hub. It consists of motherboards carrying power modules and gateway modules for connection to PROFIBUS DP. The SK3 is located at the end of the homerun cable in the control room cabinet. It detects the spark and switches it off. The SK3 offers:
The DART Power Hub is first to introduce load-sharing redundancy. It balances the load current between the power modules. The power module operates in the best, most energy-efficient state, reducing cooling requirements for the cabinet and increasing service life.
Its connection to PROFIBUS DP is ‘transparent’. This means that PROFIBUS PA devices appear as PROFIBUS DP slaves. The SK3 itself requires no configuration. This simplifies system configuration. Additionally, the SK3 includes one PA Master per segment offering fast and reliable communications. A compact SK3 version for small installations powers two segments.
The DART Segment Protector provides outputs with short-circuit protection. Outputs are certified Ex ib IIC for intrinsically safe instruments. The main attributes are:
Segment Protectors come in practical stainless steel or GRP enclosures with cable glands. Options and accessories easily selectable.
All DART Fieldbus components are developed with the highest demands on reliability and durability built-in. With the experience at Pepperl+Fuchs our products deliver: