Industrial PLC Hardware Design

I’m developing an industrial-grade programmable logic controller intended to run closed-loop control systems on a factory floor. The job centres on hardware only: turning the functional specification I will supply into a production-ready board set.

At a minimum I need complete schematics, an optimised PCB layout, recommended component stack (with industrial-temperature parts), and manufacturing files ready for prototype build. The design must tolerate harsh electrical noise, accept 24 V DC field power, expose isolated digital and analogue I/O, and provide standard fieldbus options such as Modbus-RTU over RS-485; extra Ethernet or CAN is a plus if it fits within the available board footprint.

Acceptance is straightforward: the first-run prototype should power up, enumerate over the chosen bus, toggle outputs under bench test, and meet 500 V isolation on every opto-isolated channel. I’ll handle firmware once hardware is proven, so clear pin maps and test points in the documentation are essential. CAD files in Altium or KiCad are both fine, as long as Gerbers, pick-and-place, and BOM (with second-source parts) arrive in standard formats.

If this scope is clear, jump straight into the schematic draft; I’ll supply the I/O count and enclosure dimensions as soon as we start.