Tamper-proof safety transponder
24 November 2016
SICK has launched the STR1, a Transponder Safety Switch that uses non-contact RFID technology to provide highly-reliable and tamper-proof personnel protection on removable guards to PLe/SIL3, with easy installation and safety system integration.
The SICK STR1 can be installed individually or in series with up to 30 units, using T-junctions or the SICK Flexi Loop safety sensor cascade whilst still achieving PLe (EN ISO 13849) and SIL3 (IEC62061).
“Two big challenges with non-contact safety switches on removable guards are the mounting requirements and their susceptibility to tampering,” SICK’s UK safety specialist and FS engineer (TUV Rheinland #13017/16) Dr Martin Kidman said.
“Large door offset tolerances and high levels of shock and vibration cause reliability issues. Additionally, the temptation for operators to defeat the guard because of piece-working or a lack of special modes of operation, for example, makes manipulation a huge problem.”
To allow for flexibility during mounting, the STR1 has three different actuators, each of which can be actuated from four different mounting directions. With its compact VISTAL housing, the STR1 offers impressive mechanical stability, high EMC immunity and an IP67 enclosure, to ensure excellent reliability in harsh environments.
The STR1 continually self-monitors its semiconductor Output Safety Switching Devices (OSSDs) to detect failures and has LED status indicators for fast diagnostics. Three coding types are available: universally-, unique-, and individually -coded. For applications that are susceptible to manipulation, uniquely- and permanently-coded variants can be used dependant on the risk.