Omron NX-SID Series User Manual page 421

Appendix
Program
A
Precautions for Safe Use
• Test the functionality every six months to detect welded contactor contacts.
• The customer is responsible for attaining conformance of the entire system to standards.
• To detect electrical and mechanical failures, use a combination of redundant semiconductor
output contacts and redundant mechanical output devices.
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NX-series Safety Control Unit User's Manual (Z930)