In today's sub-10 nm fabs, a single communication glitch can scrap millions of dollars in wafers, so the control network must behave like a deterministic nervous system. Rockwell answers this with CompactLogix PACs that run EtherNet/IP at 20 ms RPI, embedding motion, analog and safety I/O in one chassis to govern lithography stages, etch chambers and wafer-handling robots while exchanging tag-based data with MES and tool APC layers.
Where stability trumps speed, legacy SLC 500s still guard the clean-room: their 1747-SDN DeviceNet cards wire temperature, humidity, particle and pressure sensors to ISO 14644-1 limits, keeping laminar-flow fans and chemical scrubbers in perfect balance.
Siemens covers the utilities through S7-300 CPUs on PROFIBUS-DP, polling remote ET200 stations for ultra-pure-water flow, chilled-loop delta-P and toxic-gas cabinet status, then cascading PID loops inside the TIA portal to cut HVAC energy while preventing any excursion that could contaminate product.