Yokogawa CP345 S1 Central Processor Module

Configured for high-speed logic execution in CENTUM CS 3000 control platforms, the Yokogawa CP345 S1 (CP345-S1 Central Processor Module) provides direct physical/electrical execution of real-time 32-bit regulatory control, sequence logic, and I/O scanning management.

Hardware Specifications

DCS Process Control Characteristics

• 4-20 mA HART loop protocol: The CP345 S1 serves as the central processing node for HART-enabled loops. It manages the continuous acquisition of primary process variables and parses the digital diagnostic overlays, ensuring data is synchronized with the CENTUM CS 3000 controller scan.
• FOUNDATION Fieldbus / Profibus PA connectivity: The module utilizes native protocol stacks to bridge fieldbus-connected instrumentation with the DCS control logic, supporting deterministic communication intervals essential for maintaining loop stability in distributed control architectures.
• Channel-to-channel isolation: The processor features internal isolation boundaries between its high-speed logic circuits and the rack backplane interfaces. This is mandatory to ensure that electrical transients from I/O modules do not propagate to the central processing core.
• Cold junction compensation (CJC): The CP345 S1 manages the environmental processing requirements for the control rack, maintaining the necessary precision timing and logic references to support CJC accuracy on connected analog thermocouple input cards.

Frequently Asked Questions

Q: Does the CP345 S1 support CPU redundancy?

A: Yes, the CP345 S1 is designed to operate in dual-redundant configurations. In this setup, the primary and standby processors perform continuous internal self-tests and cross-comparisons of control state registers, enabling bumpless switchover if the primary CPU encounters a hardware failure.

Q: Is the processor module hot-swappable?

A: Hot-swapping is restricted by the specific Field Control Station (FCS) rack configuration. Consult the system status registers to verify that the redundant CPU is in a "Ready" state and the process control has been safely transferred to the standby unit before initiating removal of the module.

Field Installation Guidelines

• Mounting: Seat the CP345 S1 firmly into the designated processor slot of the CENTUM CS 3000 control rack. Ensure the locking mechanisms are fully engaged to guarantee proper backplane pin contact, which is mandatory for maintaining the high-speed data bus integrity.
• Grounding: Terminate the controller chassis to the system’s primary ground bus. A low-impedance ground reference is mandatory to ensure the efficacy of internal electromagnetic interference (EMI) filters and to maintain a stable logic ground for 32-bit execution.
• Wiring: Maintain strict physical separation (minimum 150 mm) between the central processor rack and high-power AC output conduits. Use high-integrity shielded cabling for all communication ports to prevent noise injection, which is mandatory to avoid CPU interrupt overflows and data packet corruption.