The EtherCAT Terminals in the ELX series from Beckhoff have expanded through the addition of analog input terminals with built-in TwinSAFE SC (Single Channel) technology. These highly compact I/O terminals can be used to support applications in hazardous areas that require both intrinsically safe signal transmission and functional safety capabilities.
The space-saving ELX series terminals, which are certified in compliance with the specifications of the ATEX and IECEx standards, enable direct connection of intrinsically safe field devices through to Zone 0/20 based on an integrated safety barrier. The new terminal designs extended by TwinSAFE SC technology now make it possible to achieve a safety level equivalent to PL-d/Cat. 3 according to EN ISO 13849-1 or SIL 2 according to EN 62061. In this way, users can harness all process data existing in a system for safety technology, such as to monitor the speed of fans in areas sensitive to explosion hazards, for example.
The new I/Os are available as 12-mm-wide terminals with two or four analog input channels for 0/4…20 mA, and for RTD resistance sensors, thermocouples/mV and strain gauges. Furthermore, a single-channel terminal is available for the direct connection of intrinsically safe incremental encoders, which evaluate a diagnostic-enabled NAMUR signal in accordance with IEC 60947-5-6.
With the aid of TwinSAFE SC technology, it is possible to make use of standard signals for safety-related tasks in any network or fieldbus system. The data from a TwinSAFE SC terminal is fed to the TwinSAFE Logic, where it undergoes safety-related multi-channel processing. The data originating from different sources are analyzed, checked for plausibility and submitted to a “voting” process. This is done by certified function blocks, such as Scale, Compare/Voting (1oo2, 2oo3, 3oo5), Limit, etc. For safety reasons, however, at least one of the data sources must be a TwinSAFE SC component.