Siemens SIMATIC S5 CPU 947 Central Processing Unit 256KB 6ES5947-3UA22

Description

The 6ES5947-3UA22 is a high-performance Central Processing Unit (CPU) from the Siemens SIMATIC S5 series. Designed for the S5-135U, S5-155U, and S5-155H systems, this CPU 947 provides robust processing power and a substantial 256 KB memory for demanding automation tasks. It is an essential component for maintaining legacy systems and ensuring operational continuity without the need for a full-scale migration.

Specifications

• Manufacturer: Siemens
• Product Line: SIMATIC S5
• Model: CPU 947
• Part Number: 6ES5947-3UA22
• Memory: 256 Kbytes
• Programming Interface: 15-pin D-Sub (for PG connection)
• Compatible Systems: S5-135U, S5-155U, S5-155H

Label Info

• Siemens SIMATIC S5
• MLFB: 6ES5947-3UA22

Application

This CPU is ideal for complex control applications in manufacturing, process control, and material handling systems that rely on the proven Siemens S5 platform. It is a direct replacement part for existing S5-135U/155U installations, extending the life of critical machinery.

Country of Origin

Made in Germany.

CO2 Impact

By reusing this industrial part, you are contributing to a more sustainable circular economy, avoiding approximately 24 kg of CO2 emissions associated with the production of a new component. This is equivalent to saving the emissions of a 120-kilometer car journey.

Availability

This is an obsolete item, but it is available from our stock. Order now from PLC2Day for expert support and fast delivery.

FAQ

Question?
Can I use this CPU 947 in any SIMATIC S5 rack?

Answer:
No, the 6ES5947-3UA22 is a high-performance CPU designed specifically for the S5-135U, S5-155U, and S5-155H programmable controllers. It is not compatible with smaller racks like the S5-95U, S5-100U, or S5-115U.

Question?
What programming software and cable are required for this CPU?

Answer:
This CPU is programmed using Siemens' legacy STEP 5 software. You will need a specific programming cable that connects your programming device (PG) to the 15-pin D-Sub port on the front of the module.

Question?
Does this module require an external memory submodule to retain its program?

Answer:
The CPU 947 has onboard RAM for the user program. To ensure program retention during a power outage, it relies on a backup battery installed in the power supply module of the S5 rack. It does not use plug-in EPROM or EEPROM submodules like some other S5 CPUs.

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Last Update: Friday, March 13, 2026