Product Overview

The 6ES5490-7LB12​ is a screw-terminal front connector within Siemens’ SIMATIC S5 490 accessory family, engineered as the 24-pin, screw-type wiring interface that bridges S5 I/O module front faces to the field-terminated cables in the panel. It succeeds the 6ES5490-7LB11​ (the original 24-pin screw-type in the 490 lineup) and belongs to the broader 490 front-connector ecosystem that also includes 7LAxx (spring-clip / crimp style, 24/46-pin), 7LB21 (46-pin screw), 7LC11 (47-pin spring, S5-115U/H/F-specific), and 8MAxx/8MBxx (40-pin variants for S5-90U/95U/100U). The 6ES5490-7LB12​ is not a functional I/O module—it carries no electronics, no A/D, no logic—but it is the critical removable termination interface: when an S5 I/O module (AI, AO, DI, DO) needs replacement, the 6ES5490-7LB12​ stays wired to the field cables, unlatches from the failed module, and transfers to the replacement module, preserving all 24 field wire landings and eliminating re-termination time during a line-down event.The 24-pin count on the 6ES5490-7LB12​ positions it for S5 modules whose front-connector interface is 24 pins rather than the more common 40-pin (used by the Compact U and 7L/8M modules such as 432 DI, 456 DO, 464 AI, 470 AO—those take the 6ES5760 40-pin family). The 24-pin 490-series connectors typically serve narrower S5 module formats or specific S5-90U/95U/100U/ET 100U I/O where pin count is reduced, as well as certain S5-115U special-function modules. Screw-terminal construction (versus the 7LAxx spring-clip or 7LCxx spring-cage alternatives) is the differentiating choice here: screw terminals tolerate higher vibration endurance and are the preference in heavy-industry S5 cabinets (metals, mining, marine, compressor packages) where panel transport vibration or nearby hammer-blow equipment can work spring-clip connections loose over decades. The 6ES5490-7LB12​ is rated for 24 V DC typical S5 field wiring (with UL approval for broader voltage classes per S5 490 family qualification) and operates across the standard S5 ambient range, making it a “buy-once, stock-for-all-24-pin-490-modules” spare.Like all S5 490 accessories, the 6ES5490-7LB12​ is long past Siemens’ active PLM—the entire S5 platform reached PM500 deletion—so verified stock through S5-obsoletion channels is the procurement path. For maintenance teams sitting on S5-90U/95U/100U cells or mixed S5-115U racks with 24-pin 490-interface modules, keeping 5–10 6ES5490-7LB12​ on the shelf (they’re small, cheap, non-perishable) prevents a “module failed but the replacement needs a different connector” mismatch during a midnight swap.

Technical Specifications