Siemens 6ES5491-0LB11 SIMATIC S5 Adapter Casing is an adapter capsule for the S5-115U/F controllers (design ES 902) that enables connection of up to two S5-135U/155U expansion modules to a single S5-115U base unit. It provides the required mechanical and electrical interface to mount the additional modules in classic SIMATIC S5 installations. This part is documented as a replacement/adaptation casing for S5-115U/F builds and is used to extend the system's I/O capacity by adding up to two expansion modules, making it a direct fit where S5-115U backplanes and ES 902 enclosures are in use.
