June 7, 2011 - Suitable for installation in zone 2 or in safe areas, R. STAHL's 9410 series of compact field device couplers features protection for the trunks against feedback through short circuits in the spurs. The cost-efficient FDCs connect up to twelve FOUNDATION fieldbus H1 or Profibus PA devices via detachable screw terminals with locking screws to a non-intrinsically safe high energy trunk.
Users can connect fieldbus devices with Ex nA ignition protection and, with a voltage-limited power supply module, Ex ic or Ex nL devices as well as Ex d and Ex n equipment from zone 1. A power management limits any short circuit currents to one device per coupler: if a spur is affected, it is shut down until the short circuit is removed. This spur protection ensures that the current absorbed by the trunk and the power dissipation are minimised under all operating conditions. In addition to the automatic shutdown, a red LED indicating a short circuit is activated for the affected spur. Additionally, the coupler activates one device after the other as soon as the trunk voltage exceeds 9 V during fieldbus start-up.
This soft start function limits the starting current of the segment by up to 50 %. The couplers are suitable for easy upright or horizontal installation on DIN rails. R. STAHL also provides various enclosure types made from GRP or stainless steel according to customer requirements. Accessories include suitable fieldbus power supplies, external terminating resistors and a free engineering software tool that enables easy segment design for FF and Profibus PA segments.
