E-Stop - PLC Programming & Automation

Two Zones That Disagree About Who Owns the Box: The Handshake That Restarts a Stuck Conveyor

Zones 4, 5 and 6 in side view with the 900 mm blind length between PE4 and PE5 marked, a 600 mm carton standing 30 mm short of PE5 with every ownership bit clear, and the next carton on PE4 about to be released into it

Why an accumulation zone stops with nothing on it: how the zone ownership handshake half-completes, the one-state fix, and the run that restarts it.

Restarting a Fully Accumulated Conveyor After an E-Stop Without Stalling the Line

by PLC

Plan of the twelve full zones after the E-stop, a carton on every eye and two coasted past theirs, the seconds until each zone first moves, and the five things that have to be true before Line_Running

A conveyor restart after an E-stop with twelve zones full: clear F059, give each PowerFlex 525 its start edge, stagger the drives, let the wave run.

Functional Safety PLC: Risk Assessment to PLd Architecture

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.

Wireless PLC Communication: Wi-Fi, Radios and Cellular

by PLC

Timing chart of a wireless link: the radio link drops, I/O data stops arriving, the connection fault bit sets after the timeout window expires, the line stops, and everything recovers only after the link returns and the logic is reset

Wireless PLC communication done properly: choosing Wi-Fi, 900 MHz radios or cellular, RPI and timeout budgets, antennas, roaming, and link loss logic.

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

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.