iso 13849 - PLC Programming & Automation

PLC Safety Interlock: Dual-Channel E-Stop on GuardLogix

September 12, 2026January 29, 2024 by PLC

Timing chart of a dual channel E-stop: channel A opens, channel B follows shortly after inside the discrepancy time, the safety output drops at once, the E-stop is released, and the output only returns after the reset button is pressed and released

When a standard interlock is not enough, how to wire and configure a dual-channel E-stop on GuardLogix safety I/O, and the reset rule nobody may break.

Functional Safety PLC: Risk Assessment to PLd Architecture

September 13, 2026January 3, 1970 by PLC

Timing chart of a guard door safety function: the door opens, the safety function result drops shortly after, the contactors release inside the response time budget, and the output only returns after a manual reset pulse with the door closed

How functional safety works on a PLC job: the ISO 13849-1 risk graph, PLr, category 3 architecture, MTTFd, DC, CCF, a PFHd budget and SISTEMA.