Siemens6FX1136-8BA01Sinumerik 880 / 880M Multiport Memory Board with Real-Time Clock — 128 KB Battery-Backed RAM, NC Ready 2 Contact, Measuring Pulse Inputs

Product Description

What this part is

This is the multiport memory board with clock for the Siemens Sinumerik 880 and 880M CNC control — Siemens designation BGR MULTIPORT, MIT UHR (ZENTRALPUFFERUNG, INTEGR. RAM). It is a Euro-format plug-in card that seats in the Sinumerik 880 rack and connects to the NC rack backplane bus. It does three jobs that a bare description of “circuit board” completely hides: it provides the centrally buffered, battery-backed RAM that retains machine parameters and the system buffer through a power-down, it carries the real-time clock the control uses to keep system time, and it hosts a set of central housekeeping functions for the rack.

Decoding the order code

6FX: Siemens numerical control and feed drive product area (Sinumerik).

1136: the Sinumerik 800-series card block. Its sibling 6FX1136-3BA01 is the Servo-CPU board for the same rack, which is a good illustration of how much the last digits change the function.

8BA01: the multiport memory board with clock and central buffering.

Also written 6FX11368BA01, 6FX1136 8BA01 and 6FX1136-8BA-01. The number 570 368 9101.01 on the board is a Siemens internal drawing or PCB layout number and is worth keeping as a search term; the orderable number is 6FX1136-8BA01.

Published specifications

Platform: Siemens Sinumerik 880 and 880M.

Module description: multiport memory board with clock, central buffering, integrated RAM.

Memory: 128 KB lithium-battery-backed Link RAM, retaining the system buffer and machine parameters through power-down.

Real-time clock: integrated CMOS RTC — the control’s system time depends on this board.

Bus functions: bus priority logic control and system clock pulse generation.

Measuring inputs: 2 measuring pulse inputs for in-process measurement functions.

Relay output: NC Ready 2 contact.

Monitoring: temperature monitoring circuit.

Form factor: Euro-format plug-in card, mates to the 880 rack backplane bus.

Mounting data

Slot allocation: Sinumerik 800-series racks are slot-specific and cards are not freely movable between slots.

Bus connection: the card mates to the NC rack backplane bus through its Euro-format edge connector.

What these specs mean in practice

Because this board holds both the battery-backed parameter RAM and the real-time clock, its failure mode is distinctive and often misdiagnosed. A control that loses machine parameters on every power-down, or that comes back with the wrong date and time, or that reports a parameter checksum fault after a weekend shutdown, is pointing at this board or its backup battery — not at the CPU. A flat lithium cell produces exactly the same symptoms and costs a fraction as much.

The NC Ready 2 relay contact matters for safety and interlock wiring. It is a hardware output the machine builder typically uses in the enable chain, so a failed relay on this card can present as a machine that will not enable at all, with no obvious NC alarm.

The two measuring pulse inputs are what the control uses for in-process probing and measurement cycles. On a machine with a touch probe or in-cycle gauging, this card is in that signal path.

Sinumerik 880 predates 840D by a long way, so this is deep legacy territory. Boards are not being made, documentation is scarce, and a working spare on the shelf is the difference between a day of downtime and a month of it.

Quantity and configuration

Board only, one card. The lithium backup battery, the Sinumerik 880 rack or card cage, the backplane, the Servo-CPU board and other rack cards, and ribbon or backplane cabling are each ordered separately. This is a rack card and operates as part of an 880 rack.

Interchange guidance

Search forms include 6FX1136-8BA01, 6FX11368BA01, 6FX1136 8BA01 and the board marking 570 368 9101.01. 6FX1136-3BA01 is the Servo-CPU board for the same rack, a different card in the same family, not an equivalent. Sinumerik 880 cards are strongly tied to the rack generation and to the machine’s software version; match the full order code. Siemens has long discontinued the Sinumerik 800 series with no factory replacement path; surplus, reman and specialist board repair are the supply channels.