Overview
The Siemens 6ES5 103-8MA03 is a SIMATIC S5 CPU 103 central processing unit engineered for the S5-100U automation platform. This model is a CPU module for the Siemens S5-100U system, suitable for small to medium-sized automation applications. The CPU module features an internal power supply, built-in memory, and the ability to support a range of I/O and analog modules, making it versatile for various industrial applications. A Germany-manufactured spare part, this unit provides the proven durability and precision Siemens is known for in industrial control environments.
Key Features
- Contains 20 Kbytes of internal RAM representing the total working memory available for both program logic and data storage
- Supports up to 256 digital inputs and outputs combined, and up to 16 analog inputs and outputs combined
- 32 timers ranging from 0.01 to 9990 seconds and 32 counters with up to 999 for up/down counting
- Binary operation execution time approximately 7 µs (Normal), 70 µs (Test); Word operation approximately 40 µs (Normal), 125 µs (Test); Monitoring time approximately 350 ms
- Integrated lithium backup battery (3.4V, 850 mAh) with approximately 5-year service life
- Compatible with STEP 5 programming language and legacy S5 automation projects
Technical Specifications
Input Voltage: 24 V DC (18 to 34 V permissible range) with Output Voltage: V1 (for I/Os): +9 V, 1 A; V2 (for programmer): +5.2 V, 0.65 A. The unit measures 91.5 x 135 x 120 mm (3.6 x 5.3 x 4.7 inches) and weighs approximately 0.65 kg (1.4 lbs). Maximum 10,240 statements (STL/LAD/FBD instructions), each consuming 2 bytes of RAM.
Typical Applications
The 6ES5 103-8MA03 is ideal for legacy industrial automation systems and maintenance applications where S5-100U platform processors are required. Common uses include process control, manufacturing automation, assembly line management, and HVAC systems that rely on proven S5 architecture. Its compact form factor and reliable operation make it suitable for retrofit and emergency replacement scenarios in established facilities using Siemens SIMATIC S5 control platforms.
Compatibility & Replacements
This CPU module integrates with the SIMATIC S5-100U system and supports I/O expansion modules, analog modules, and memory submodules including optional EPROM/EEPROM modules. Organizations migrating from legacy S5 systems may consider Siemens migration tools and adapters for converting S5 programs to TIA Portal; the S7-1200 offers 100KB+ program memory and modern Ethernet connectivity, though this unit remains the original drop-in replacement for existing S5-100U installations.
