Safety PLC configuration and proof-test programme design
Safety PLC engineering covers configuration, programming, and proof-test procedure development for TÜV-certified safety PLCs (Triconex, HIMA, AB GuardLogix). Proof tests verify that each SIF still meets its SIL claim.
Define proof-test scope per IEC 61511 Phase 14 covering each SIF with proof-test interval (T1) from PFD calculation; identify revealed (DD) vs unrevealed (DU) failure modes per FMEDA; design test coverage to detect DU failures.
Author proof-test procedure per SIF — sensor stimulus (calibrator, valve manifold), logic solver verification, final element actuation, end-to-end loop test; specify proof-test coverage (PTC) percentage with documented justification; align with vendor Safety Manual.
Specify PST for SIL ≥2 SDV / BDV where applicable; calculate PST coverage (typically 60–80% of DU failures); design online PST with monitoring of position-time signature; integrate with diagnostic and maintenance workflow.
Specify bypass authorisation procedure per IEC 61511 Cl.11.8 — operator role authorisation, mandatory compensating measures, time-limit, audit log; design override management with annunciation, automatic timeout, and MOC trigger for extended override.
Design proof-test record format with as-found / as-left values, failure findings, MOC triggers; specify electronic record-keeping with IEC 61511 audit-trail compliance; align with TÜV / exida FSA Stage 4 operational evidence requirement.
Periodically recalculate PFD with observed failure data; adjust proof-test interval per IEC 61511 Cl.11.9 management of functional safety; trigger MOC for any SIF interval / coverage change; align with SIL register revalidation cycle.
Complete Safety PLC Engineering & Proof Test Procedures scope — every calculation, drawing, specification, and construction support activity.
Speak with our team to scope an engagement tailored to your facility, regulatory context, and lifecycle stage.