Siemens 6ES5 948-3UR21 · SIMATIC S5-135U CPU 948
S5-135U CPU 948 processor with 1.5 MB memory submodule. For German machine tools that never left the S5 world.
- SKU
- MS-IP-0233
- Era
- 1950-2000
- Condition
- Removed from service, tested, memory submodule seated. 90-day warranty.
- Dimensions
- 9.25" H × 1.6" W × 7.9" D
- Weight
- 3 lb 2 oz
- Provenance
- From a shuttered Krauss-Maffei tooling shop in Baden-Württemberg, imported 2022.
- Category
- Obsolete Industrial Parts
- Tags
- siemenssimatic-s5cpu-948german-machineryobsolete
The CPU 948 was the top of the S5-135U line — the processor that ran the largest Siemens installations of the late eighties and nineties. This particular one is the 3UR21 variant with the 1.5 MB internal RAM submodule, still socketed and formatted.
Siemens ended S5 production in 2003 and spares support in 2013. Every year a few more of the German injection-molding houses, the machine-tool retrofits, and the older Bosch-Rexroth-controlled presses come looking for a working 948 because the migration to S7 was never budgeted.
We've programmed it, cycled it in a 135U rack, and confirmed clean handoff on the K-bus. The backup battery is fresh.
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