Attributes . can reach PL e/category 4 for normally open relay contact ISO 13849-1 || can reach SILCL 3 for normally open relay contact IEC 62061 || can reach SIL 3 for normally open relay contact IEC 61508 || can reach PL c/category 1 for normally closed relay contact ISO 13849-1 || can reach SILCL 1 for normally closed relay contact IEC 62061 || can reach SIL 1 for normally closed relay contact IEC 61508 . Names