PLC - PLC Programming & Automation

EtherNet/IP PLC Communication: Setup, RPI and Faults

Timing chart of EtherNet/IP implicit I/O at 10 ms RPI showing producer and consumer packets against a 25 ms periodic task scan

Set up EtherNet/IP between a Logix controller, remote I/O and a drive: RPI, unicast vs multicast, MSG paths, and the fault codes you will really see.

PLC MES Integration: Tags, Handshakes and Work Orders

by PLC

Timing chart of an MES to PLC work order handshake showing Request from the MES, Ack from the PLC, Done when the order is latched, and both bits clearing after Request drops

What MES really needs from the controller: OEE counters, downtime reason codes, a work order UDT, a request and acknowledge handshake, an OPC UA bridge.

ControlLogix Ladder Troubleshooting, Rung by Rung

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Ladder rung with a bug: XIC Conv3 Start in series with XIO Conv3 EStop driving OTE Conv3 Run, with no seal-in branch around the start contact

A rung by rung ControlLogix ladder troubleshooting method: read the highlighting, use cross reference and search, find double coils, read the fault record.

EtherCAT PLC Systems: Cycle Time and Distributed Clocks

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Timing chart of a 1 ms EtherCAT cycle showing the task window, the frame on the wire, and the SYNC0 pulse that applies outputs on every slave at the same instant

Set up an EtherCAT bus in TwinCAT 3: ESI files, scanning the line, picking a cycle time, distributed clocks and the CRC counters that find a bad cable.

PLC Programming for Beginners: Your First Working Project

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Ladder rung with Start in parallel with the Conveyor seal-in contact, in series with a normally closed Stop contact and a normally closed Overload contact, driving the Conveyor output coil

PLC programming for beginners without the theory dump: pick a simulator, write a start/stop rung, add a timer and a counter, wire one HMI button.

PLC Hardware Components and the Software That Uses Them

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Timing chart showing a field input rising, the input image bit following at the next input scan, the coil in logic changing during the program scan, and the physical output finally switching after the output scan, about one scan behind the field

What is in a PLC rack and how the software sees it: power supply budget, CPU memory, I/O cards, tasks and routines, and tags against S7 addresses.

Wireless PLC Communication: Wi-Fi, Radios and Cellular

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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.

Functional Safety PLC: Risk Assessment to PLd Architecture

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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.