SIEMENS6FX1138-6BB01SINUMERIK 880 PLC-CPU Card, Type 135WB/COP, 128 KB RAM, Software Version 4.x

Product Description

What this part is

This is a Siemens SINUMERIK 880 PLC-CPU board, type 135WB/COP with 128 KB RAM — the processor that scans and solves the machine’s PLC ladder inside the SINUMERIK NC rack. On an 880 control the CNC side handles the part program and the interpolation, and this card handles everything else the machine does: tool changer sequencing, coolant, hydraulics, guarding interlocks, operator panel logic.

It is a CPU-tier module, not an I/O card and not a communications board. That distinction is the single most common ordering error on this platform, because the 6FX1138 block covers CPU cards, memory cards and interface cards under numbers that differ by two characters. If the rack’s ladder is not running, this is the class of card you want. If a group of field points is dead, it is not.

Decoding the order code

6FX1 — Siemens SINUMERIK NC hardware prefix (the 6FX1 generation covers SINUMERIK 3, 8, 810/820 and 880 control racks).
138 — the plug-in processor and memory card block within that generation.
-6BB01 — the specific card: SINUMERIK 880 PLC-CPU 135WB/COP, 128 KB RAM. The 6 in the first position of the suffix marks the 880-generation card — the -5Bxxx suffixes in the same block are SINUMERIK 810/820 and 805SM cards and are a different control entirely. -6BL01 is the sister PLC 135WB CPU board in the same 880 range.
135WB — the Siemens SIMATIC S5 processor type the card is built around; COP denotes the coprocessor build.

Firmware and software version: read this before you buy:
This card is published as the 128 KB RAM PLC-CPU for software version 4.x. On a SINUMERIK 880 the NC software version, the PLC-CPU card and the machine’s PLC program are a matched set: a card built for one software band will boot in a rack running another and then fail to accept or correctly execute the machine program. Check the software version on your control’s diagnostic screen and the card number on the board you are replacing before ordering. This is why an 880 CPU card that is physically perfect can still be the wrong part.

Published specifications

Function: integrated PLC processor for the SINUMERIK 880 CNC control
Type designation: PLC-CPU 135WB/COP
User memory: 128 KB RAM
Software band: version 4.x
Form: plug-in card for the SINUMERIK 880 NC rack backplane

What these specs mean in practice

128 KB is the figure that decides whether a machine’s ladder fits, and on an 880 that ladder is usually large: a machining centre with a chain magazine, pallet changer, probing and full guarding interlocks fills a PLC program quickly. If your existing card is a smaller-memory variant, moving up buys headroom; if it is a larger one, this card will not hold the program and no amount of optimisation will change that. Because the memory is RAM, the rack’s backup battery is a maintenance item and not an accessory — a flat battery on a stored or unpowered card means the PLC program is gone and has to be reloaded from the machine builder’s archive.

Quantity and configuration

One card ships. No NC rack or backplane, no CNC CPU or NC memory cards, no EPROM or memory submodules, no battery, no operator panel, no I/O modules, no programming cable or PG unit, no software and no documentation are included. Plan on a fresh backup battery and the machine’s PLC archive before commissioning.

Installation and setup notes

Power down and lock out the control cabinet before withdrawing or inserting the card — SINUMERIK rack cards are not hot-swappable and a live insertion can corrupt the NC memory as well as damage the board. Note the exact slot, and note the position of every jumper and any memory submodule on the card you are removing; 6FX1 cards are slot-specific and the rack’s card schedule is usually printed inside the cabinet door. Handle by the edges and the extraction handle. Clean the gold edge fingers with isopropanol and a lint-free wipe rather than an abrasive; on this generation of control, intermittent faults are more often a fretted edge connector than a dead card, so reseat the neighbouring cards while the rack is open. Fit a good battery, reload the PLC program, then power-cycle deliberately and confirm the program is retained before releasing the machine.

Interchange guidance

Searched as 6FX1138-6BB01, 6FX11386BB01, 6FX1 138-6BB01, 6FX1138 6BB01, 6FX1138-6BBO1 (the letter-O misreading is common) and SINUMERIK 880 PLC CPU 135WB. 6FX1138-6BL01 is the sister PLC 135WB CPU board in the same 880 range and is the closest relative — carried as a cross-reference, but the memory and build differ, so confirm against your card schedule. The 6FX1138-5BB03 and -5BB04 cards in the same numbering block are SINUMERIK 810/820 and 805SM CPU modules, a different control generation entirely, and are listed here only so you can rule them out. SINUMERIK 880 is long obsolete; Siemens’ current equivalents are SINUMERIK 828D and 840D sl, which are complete control retrofits rather than card swaps. Support for the 880 runs through repair-exchange and surplus, which is why a known-good spare CPU card is worth keeping on the shelf for a machine still earning.