Articles - PLC Programming & Automation

PLC MES Integration: Tags, Handshakes and Work Orders

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.

EtherCAT PLC Systems: Cycle Time and Distributed Clocks

by PLC

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.