Description

The Siemens 6ES5103-8MA03 is a central processing unit (CPU) module from the SIMATIC S5 series, specifically engineered for the S5-100U programmable logic controller system . As the core control brain of the PLC, this processor module executes user programs, manages system operations, and coordinates all connected I/O modules within the automation architecture .

The Siemens 6ES5103-8MA03 represents a compact controller solution with 20KB of memory capacity, integrating essential control functions into a single module. Designed for small to medium-scale automation applications, this CPU supports the S5-100U expansion framework and provides reliable processing power for basic to intermediate control tasks .

 

Application Scenarios

In a food processing plant that has been operating S5-100U-controlled packaging lines for over two decades, the original CPU module began exhibiting intermittent faults, causing unplanned production stoppages. The maintenance team sourced a Siemens 6ES5103-8MA03 as a direct drop-in replacement. With the CPU’s 20KB memory storing the existing STEP 5 program, the module was installed in minutes, and full production was restored without any modifications to the existing I/O wiring or control logic. The plant’s engineering lead noted that securing a Siemens 6ES5103-8MA03 spare saved an estimated 48 hours of downtime that would have been required for a full system migration to a modern platform .

A custom machinery OEM standardized their control platform on the Siemens 6ES5103-8MA03 for its balance of processing capability and expandability. With support for up to 256 digital I/O points and 16 analog I/O channels combined , the module provided sufficient capacity for their industrial washer control systems while maintaining compatibility with their existing S5-100U I/O modules. The integrated 24V DC power supply and built-in short circuit protection added operational reliability in demanding washroom environments .

 

Parameters

Main Parameters	Value/Description
Product Model	Siemens 6ES5103-8MA03
Manufacturer	Siemens
Product Category	Central Processing Unit (CPU) for SIMATIC S5-100U
Memory Capacity	20 KB
Programming Interface	1x 20mA (TTY) Current Loop Interface
Power Supply (Input)	24V DC (18 to 30V DC range)
Current Consumption	1A @ 24V DC
Power Loss	11.6W
Output Voltage (I/Os)	+9V @ 1A
Output Voltage (Programmer)	+5.2V @ 0.65A
Digital I/O Capacity	Up to 256 inputs and outputs combined
Analog I/O Capacity	Up to 16 inputs and outputs combined
Timers	32 timers (0.01 to 9990 seconds)
Counters	32 counters (up to 999 for up/down counting)
Memory Submodule	EPROM/EEPROM (required for program storage)
Operating Temperature	0°C to +55°C
Weight	Approx. 0.59 – 0.69 kg
Protection	Short Circuit Protection