Automation hardware
PLC, HMI & Industrial Automation replacement guide
Identify PLCs, I/O modules, HMIs, industrial PCs, safety controllers, remote I/O, gateways, communication modules, and automation hardware by platform, firmware, network, and electrical interface.
Evidence boundary. Automation replacements are often migration projects rather than drop-in swaps. Track firmware, software, rack, network, I/O, safety, and application dependencies explicitly.
Items covered01 · 15 component types
- PLCs
- Digital I/O modules
- Analog I/O modules
- HMIs
- Industrial PCs
- Motion controllers
- Servo drives
- Safety PLCs
- Remote I/O
- Industrial Ethernet switches
- Protocol gateways
- Fieldbus couplers
- Communication modules
- Machine-vision controllers
- Robot controllers
What to capture02
Manufacturer, platform, exact catalog number, series, and hardware revisionRecord this before searching for a substitute.
Firmware, software compatibility, memory, and licensing requirementsRecord this before searching for a substitute.
I/O type, channel count, voltage, isolation, and field wiringRecord this before searching for a substitute.
Backplane, rack, terminal block, connector, and mountingRecord this before searching for a substitute.
Network protocol, topology, safety rating, and system dependenciesRecord this before searching for a substitute.
What must match03
Platform and firmware compatibilityConfirm it against the original equipment, duty, and source documentation.
I/O electrical characteristics and field wiringConfirm it against the original equipment, duty, and source documentation.
Rack, backplane, terminal, and mechanical fitConfirm it against the original equipment, duty, and source documentation.
Network, addressing, protocol, and software supportConfirm it against the original equipment, duty, and source documentation.
Safety certification, redundancy, and migration requirementsConfirm it against the original equipment, duty, and source documentation.
Common searches04
What replaces this obsolete PLC?
Can I replace an HMI with a newer model?
What I/O module is compatible with this rack?
What must be migrated when an automation part is discontinued?
Authoritative starting points05
Source-backed field guides1 guide