Siemens 6ES5948-3UR23 SIMATIC S5 Central Processing Unit

The Siemens 6ES5948-3UR23, also cataloged as the 6ES5948-3UR23 Central Processing Unit, operates as a dedicated hardware component for executing high-speed control logic and arithmetic computations within SIMATIC S5-155H fault-tolerant automation platforms.

Hardware Specifications

Backplane Bus Communication Velocity and Deterministic Networks

The 6ES5948-3UR23 utilizes internal parallel bus drivers to optimize backplane bus communication velocity across the internal S5 subrack. This high-performance hardware processor handles high I/O density scaling and massive data structures with deterministic execution cycle times. It coordinates with the redundant peer CPU using dedicated synchronization links. The unit enforces absolute data alignment and cycle parity across the inter-processor connection. This ensures synchronized firmware flash compatibility and immediate bit-stream tracking during high-availability automation processes connected via PROFIBUS DP or Industrial Ethernet nodes.

Frequently Asked Questions

Q: What function does the "R" suffix on this CPU 948R designate?

A: The "R" designates built-in redundancy hardware support, featuring onboard synchronization interfaces required to run a hot-standby pair within the fault-tolerant S5-155H architecture.

Q: Can the 1600 KB RAM internal memory be expanded further?

A: Yes. The internal memory allocation can be adjusted or supplemented using approved external Siemens S5 memory submodules inserted directly into the designated front-panel memory card slots.

Q: Is hot-swapping of the 6ES5948-3UR23 CPU permitted during system operation?

A: No. The SIMATIC S5 chassis must be completely powered down before extracting or inserting the CPU module to prevent structural damage from voltage transients on the S5 backplane bus.

Field Installation Guidelines

• Subrack Insertion: Disengage all power links before insertion. Align the CPU circuit board precisely with the guide rails of the S5-155 rack, pushing it straight until the heavy multi-pin rear connectors plug completely into the passive backplane.
• Grounding Protocol: Ensure the module front plate is securely fastened with the integrated retention screws to maintain a continuous, low-impedance ground path to the main enclosure chassis ground bar.
• Electrostatic Control: Always wear a grounded ESD wrist strap and handle the module exclusively by its plastic front pull-handles to avoid injecting static charges into the internal CMOS processing logic.