System Architecture Overview

Architecture type: Redundant Central Unit (CU) + single-channel I/O bus

Rack format: 19-inch central rack, 5 HU height

I/O structure: Central rack with expandable remote I/O subracks

Hot-swap capability: Supported for I/O modules during operation

Safety and Compliance

Safety integrity level: TÜV-certified SIL 3

Standards compliance:

IEC 61508 (Functional Safety)

IEC 61511 (Process Industry Safety)

Designed specifically for high-availability Safety Instrumented Systems (SIS) requiring deterministic behavior and fault tolerance.

Core System Configuration

The standard system configuration includes:

Redundant Central Modules (CU)

Parallel operation with continuous synchronization

Hot-swappable without process disturbance

Power Subsystem

24 VDC / 5 VDC power modules

Redundant power supply design

Integrated power supervision and protection

Power Monitoring Module

F7131 power monitoring module

Provides voltage supervision and alarm signaling

Thermal Management

3 sets of redundant cooling fans

Ensures stable operation under high load and harsh conditions

I/O Bus Interface

Single-channel safety I/O bus

Supports deterministic and certified signal transmission

Expansion Capability

Supports communication and coprocessor modules

Modular system design for future scalability

I/O Expansion Capability

Supports connection of up to 16 I/O subracks

I/O subrack size: 4 HU (19-inch)

Hot-swappable I/O modules, minimizing maintenance downtime

Compatible with a wide range of HIMA safety I/O modules (DI, DO, AI, AO, F&G, etc.)

Power Supply Specifications

Input voltage: 24 V DC

Design: Redundant power inputs

Protection features:

Overvoltage protection

Reverse polarity protection

Ensures uninterrupted operation in critical safety environments.

Key Features
High Availability Redundancy

Redundant central modules operate in parallel

No switching disturbance during failover

Hot replacement capability significantly improves system availability (SIL3)

Safety Control Functions

Execution of certified safety interlock logic

Typical applications include:

Emergency Shutdown (ESD)

Fire & Gas (F&G) systems

Burner Management Systems (BMS)

Communication and System Integration

Compatible with expansion modules such as:

F8627X – Ethernet communication module

F8621A – Communication coprocessor

Supported protocols include:

SafeEthernet

PROFIBUS DP

Modbus (RTU/TCP, depending on module)

Enables seamless integration with DCS, PLC, and SCADA systems.

Diagnostics and Maintenance

Continuous power and system health monitoring

Module self-diagnostics and status indication

Fault alarm outputs for rapid issue localization

Designed for fast troubleshooting and reduced MTTR

 

HIMA H51q-HS Central Rack System

Typical Applications

Petrochemical and chemical SIL3 ESD systems

Fire & Gas detection and protection systems

Burner management and furnace protection

Turbine and compressor safety systems

Power generation and critical utility protection