Siemens SIMATIC S5 Modules: 6ES5095-8MA05

Technical Dossier

Product Details And Specifications

Siemens SIMATIC S5 Series Technical Notes

The Siemens SIMATIC S5 programmable logic controller (PLC) platform represents one of the most widely deployed industrial automation architectures in global heavy industry. Installed across chemical processing plants, nuclear power facilities, petroleum refineries, steel mills, and water treatment infrastructure, the S5 series established the foundational architecture for modern DCS and PLC integration. The 6ES5095-8MA05 is a compact unit within this platform, designed for space-constrained control cabinets requiring integrated CPU and I/O functionality in a single housing. Despite the series entering its end-of-life phase, the installed base remains extensive, making spare parts sourcing and lifecycle extension a critical operational requirement for plant engineers worldwide.

The Evolution of SIMATIC S5 Architecture

The SIMATIC S5 family was introduced by Siemens in the late 1970s and underwent continuous development through the 1990s. The architecture is segmented into sub-families by processing capacity and form factor: the S5-90U/95U compact units (including the 6ES5095-8MA05), the S5-100U modular micro-PLC, the S5-115U mid-range controller, the S5-135U high-performance system, and the S5-155U large-scale redundant controller.

Communication was handled via the proprietary SINEC H1 (Industrial Ethernet predecessor) and PROFIBUS protocols, with later revisions adding CP (Communications Processor) modules for integration into modern networks. The backplane bus architecture uses a parallel bus structure incompatible with the successor SIMATIC S7 platform, creating a hard migration boundary. Plants that have not migrated to S7-300, S7-400, or S7-1500 remain entirely dependent on S5 spare parts availability. Siemens officially discontinued S5 hardware production in 2013, with extended support contracts expiring progressively through 2020. As of 2026, all S5 hardware is classified as obsolete, placing procurement responsibility on specialist distributors.

SIMATIC S5 Full Catalog & Functionalities (SKU List)

Compact Units (CPU + I/O Integrated)

• 6ES5090-8MA01: S5-90U compact unit, 20 DI / 12 DO, 1KB RAM, basic relay control
• 6ES5095-8MA05: S5-95U compact unit, 20 DI / 12 DO, integrated analog I/O, 6KB RAM
• 6ES5095-8MB05: S5-95U compact unit with PROFIBUS-DP interface, extended memory
• 6ES5095-8MC05: S5-95U compact unit, enhanced diagnostics, 16KB RAM variant

CPU Modules

• 6ES5101-8UA13: S5-100U CPU module, 1KB RAM, basic instruction set
• 6ES5103-8MA03: S5-100U CPU, 4KB RAM, timer/counter extended
• 6ES5115-8MA02: S5-115U CPU, 16KB RAM, floating point capable
• 6ES5135-8MA02: S5-135U CPU, 48KB RAM, high-speed interrupt processing
• 6ES5155-8MA11: S5-155U CPU, 96KB RAM, redundancy-capable, large plant control

Digital Input / Output Modules

• 6ES5420-8MA11: 32-channel 24VDC digital input module, S5-100U rack
• 6ES5430-8MA11: 32-channel 24VDC digital output module, 0.5A per channel
• 6ES5440-8MA11: 16-channel relay output module, 230VAC / 2A per contact
• 6ES5451-8MR11: 16-channel relay output, isolated, S5-115U compatible

Analog Input / Output Modules

• 6ES5460-8MA11: 8-channel analog input, ±10V / 4–20mA, 12-bit resolution
• 6ES5470-8MA12: 4-channel analog output, ±10V / 4–20mA, 12-bit resolution

Communications Processors

• 6ES5523-3UA11: CP 523 serial communications module, RS-232/V.24 interface
• 6ES5524-3UA13: CP 524 SINEC L2 / PROFIBUS interface module
• 6ES5525-3UA21: CP 525 SINEC H1 Ethernet communications processor

Power Supply Modules

• 6ES5955-3LC41: PS 955 power supply, 24VDC input, 5VDC / 9A output, S5-115U
• 6ES5955-3NC41: PS 955 power supply, 120/230VAC input, 5VDC / 15A, S5-135U

Quality Control for the SIMATIC S5 Range

The SIMATIC S5 backplane bus and inter-module communication architecture requires specialized test procedures that differ from modern PLC platforms. DriveKNMS applies the following verification protocol to all S5 units prior to dispatch:

• Backplane bus continuity test: Verification of all parallel bus lines (data, address, control) using dedicated S5 rack test fixtures.
• CPU functional test: Execution of a standardized STEP 5 test program covering all instruction groups, timer/counter functions, and interrupt handling.
• I/O channel-level verification: Each digital and analog channel is individually stimulated and measured against Siemens published tolerance specifications.
• EEPROM / RAM integrity check: Memory modules are read, erased, and re-verified to confirm data retention and write cycle integrity.
• Communications module loopback test: CP modules are tested using protocol-specific loopback frames to verify PROFIBUS, SINEC H1, and serial interface functionality.
• Thermal burn-in: Units are operated at rated load for a minimum of 24 hours in a controlled thermal environment prior to final inspection.