the 1756-RIO hit discontinued on 12/31/25 and rockwell lists no replacement

two dates worth writing down if you still bridge a ControlLogix to old DH+ or remote I/O.

the 1756-DHRIO went discontinued 12/31/2024. the 1756-RIO followed on 12/31/2025, and rockwells own product page lists the replacement as "no planned RA replacement." not a migration part number. nothing.

that matters more than it sounds. those two modules are how a modern ControlLogix keeps talking to hardware that went in during the 80s and 90s. 1771 racks on remote I/O, PLC-5s and panelviews on DH+. plenty of plants bought a ControlLogix specifically so they would not have to rip the old network out, and the bridge module is the entire reason that worked.

so the door on new hardware is shut, and the bridge is a secondary market item now, same as the stuff it was bridging to.

how id actually rank the options.

count the DHRIO and RIO modules you run, add the spares you want, and buy them while the surplus market still has depth. no engineering, you just spend money.

there are protocol gateways that put DH+ and remote I/O onto ethernet/IP without replacing or reconfiguring the A-B hardware you already have. im working through the specifics with the manufacturer and ill post part numbers and pricing when i have them in writing instead of guessing at them here.

convert the 1771 racks with swing arm adapters. the modules and field wiring stay, the adapter and the network and the controller config change. thats a real project with a real budget, not a 2am fix.

full migration to ControlLogix or CompactLogix on its own schedule.

and the part nobody selling you parts says out loud. if you already have a spare on the shelf youre covered. if that network is scheduled to come out in the next two or three years, deep spares are wasted money.

sourcing this stuff is what i do, 1756-DHRIO, 1756-RIO, 1771 and PLC-5 hardware. i dont hold stock and i wont promise a unit before a supplier confirms it.

anybody still running DH+ in production? curious whether youre stocking spares or youre actually funded to get off it.

sourcing this stuff is what i do, 1756-DHRIO, 1756-RIO, 1771 and PLC-5 hardware. i dont hold stock and i wont promise a unit before a supplier confirms it.