Supply units and input isolators

SITRANS I

Output isolator HART (FSK) 7/8

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Overview

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Application The output isolator HART (FSK) electrically isolates an input cur-rent signal which originated in the non-intrinsically safe area from the intrinsically safe output circuit. It supports bidirectional com- munication between an actuator and a host computer or HART communicator (hand-held communicator).

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Design The output isolator HART (FSK) is comprised of a compact plas-tic housing (degree of protection IP20) and is equipped with push-in screw terminals.•The output isolator is designed for rail mounting (35mm (1.37inch))•Power is supplied optionally as a flexible low-voltage supply from a wide-input-range power supply unit (95 to 253VAC) or 24VAC/DC (universal current).•On the front are the LEDs for the power supply status indica-tion and the communication sockets for HART (FSK) commu-nication.•Input, output and power supply are electrically isolated. The SITRANS I output isolator HART (FSK) is used to control ac-tuators and designed for rail mounting (35mm (1.37 inch)).The output isolator has an intrinsically safe output from 4to20mA and "Intrinsically safe" type of protection EExia/ibIIB/IIC.

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Function Mode of operation

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Benefits The input current signal is filtered and amplified. After pulse-width modulation, the input signal is transferred to the output side through an opto-coupler. A low pass filter followed by an amplifier transforms the signal into a standardized output vari-able. The communication signals of a connected HART communicator are separated from the signal at the input, transferred electrically isolated to the output and added to the output signal again. Transmission through frequency shift keying is bidirectional and independent of the signal path. The HART communicator can ei-ther be connected across the input resistance (at least 250 •Power supply status indication through LED on front•HART (FSK) communication through communication sockets on front•Electrical isolation of input, output and power supply •Intrinsically safe output circuit•Designed for rail mounting (35 mm (1.37 inch)) â„¦ ) or to the communication socket on the non-intrinsically safe side.

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Mode of operation of the output isolator HART (FSK) Siemens FI 01 · 2008