Product Overview

The 6ES5095-8MD01​ is a Siemens SIMATIC S5-95U compact central unit — the CPU-and-I/O-integrated micro-PLC of the S5-90/95/100 family, which sat at the bottom of the S5 range beneath the rack-based S5-115U/135U/155U. While those larger S5 CPUs lived in 19″ racks with separate SM (signal module) cards, the 6ES5095-8MD01​ packs the processor, memory, 16 digital inputs, 16 digital outputs, 8 analog inputs, 1 analog output, 4 alarm digital inputs, 2 counter digital inputs, a PG programming interface, and a PROFIBUS DP-slave port — all in a ~140 mm cube that DIN-rails next to the machine it controls. The “-8MD01” suffix specifically denotes: 24 V DC supply, 1× programming interface (PG), PROFIBUS DP-slave onboard; the “-8MC01” sibling swaps DP-slave for 2× AS511 PG interfaces (no Profibus), and the “-8MA01/8MB01” variants move to 115/230 V AC supply with relay or transistor DO. The 6ES5095-8MD01​ is therefore the “DP-connected” variant — the one chosen when a standalone S5-95U node needed to sit as a slave under a S7-300/400 master or a PCS 7 OS.The CPU on the 6ES5095-8MD01​ is the S5-95U ASIC running the S5 operating system; program memory is 16 KB RAM (expandable to 24 KB with a plug-on RAM expansion — rare, most stayed at 16 KB), and data retentivity comes from an onboard supercap (≈100 h backup) plus an optional external battery module (6ES7291-8BA20) for long-term retention of counters, timers, and setpoints across extended power downs. Programming is via STEP 5 (DOS-era PG710/740, or later PG with STEP 5 for Windows) over the PG-SI interface on the front; the 6ES5095-8MD01​ does not support STEP 7, does not support TIA Portal, and is not S7-1200/1500 compatible — any listing claiming “TIA Portal integration” is template pollution from S7 resellers. The PROFIBUS DP-slave port uses the Siemens “Connector A” (6ES7972-0BA…) which is not included with the 6ES5095-8MD01​ (“w/o connector A” per the Siemens order text) — a frequent gotcha on first procurement.In the automation hierarchy, the 6ES5095-8MD01​ is a standalone machine-level controller or a distributed slave node. It was widely spec’d on 1990s packaging machines, textile frames, woodworking centers, small press lines, dosing skids, and building-services sub-panels — anywhere a machine builder wanted S5 robustness but didn’t need a full S5-115U rack. The S5-95U family (including the 6ES5095-8MD01) has been discontinued for years; Siemens’ migration path points to S7-1200 or S7-1500, but for plants sitting on running S5-95U nodes (“it runs, don’t touch”), the 6ES5095-8MD01​ is the targeted spare — cheaper by orders of magnitude than a full re-control.

Technical Specifications