Industrial PCs

How to choose an industrial PC for machine vision

A vision PC has to take in every image the cameras send, run the inspection in time for the line, and survive the cabinet it lives in. Work through these points in order.

1. Camera ports and bandwidth

Count the cameras and add up their data rate (pixels x frames per second x bytes per pixel). GigE Vision cameras need one network port each, ideally with PoE so one cable carries power and data; a 1 GigE port carries about 115 MB/s. USB3 Vision cameras need USB 3 ports on separate controllers when several cameras run at full speed. Line-scan or high-speed cameras (CoaXPress, Camera Link, 10 GigE) need a PCIe slot for a frame grabber or a 10 GigE card.

2. Processor and graphics

Rule-based tools (measurement, blob, pattern match, code reading) run well on a modern Intel Core i5 or i7. Several cameras at high frame rates, 3D point clouds and deep-learning inspection need more cores, more memory and often a GPU. Allow headroom: inspection time must stay below the time between parts.

3. Memory and storage

16 GB of RAM covers most single-camera systems; multi-camera and deep-learning setups want 32 GB or more. Use an SSD, and size it for image logging if failed parts must be kept for traceability.

4. I/O to the machine

Isolated digital inputs take the trigger from a photoelectric sensor or the PLC; isolated outputs drive a reject, a light strobe or an alarm. Check the count, the voltage (usually 24 V) and whether the outputs switch fast enough for the line. Serial (RS-232/485) or fieldbus may be needed for the PLC.

5. Cooling, power and mounting

Fanless PCs have no moving parts and suit dusty cabinets, but have a lower power budget; fan-cooled boxes take faster CPUs and GPUs. Check the operating temperature range for the cabinet, the supply voltage (9-36 V DC is common), and the mounting (wall, DIN rail, rack).

6. One box or a vision controller

A vision controller combines the PC with camera ports, light outputs and I/O in one unit, which saves wiring for 2-8 camera stations. A panel PC adds a touch screen for operators. For a complete station, build the system: camera, lens, light, controller and PC that fit together.