H41q/H51q Legacy HIQuad EOL Replacement & Full Scenario Selection Guide

Applicable Scenarios

New project selection for industrial safety instrumented systems (ESD/F&G/HIPPS), revamp & upgrade of existing plants, operation & maintenance iteration of installed systems, and safety‑level compliance implementation

Core Positioning: Clarify the end‑of‑life status of legacy H41q/H51q products, unify industry migration standards and full‑series product selection boundaries, prohibit non‑compliant selection for new projects, and standardize revamp & upgrade schemes for existing installations

1. Product Status: Official Lifecycle Statement for H41q/H51q (Legacy HIQuad)

As classic legacy HIQuad industrial safety systems, H41q and H51q have formally reached EOL (End‑of‑Life). These obsolete product lines are fully discontinued by the original manufacturer. New unit production has been terminated, with only limited maintenance services for existing stock equipment available. Selection for all new‑build projects is strictly prohibited.

1.1 Full List of Discontinued Hardware Models

All CPU masters, power supplies, communication modules and I/O modules of legacy HIQuad (H41q / H51q) are no longer available as new units:

• CPU Master Modules: F8650X, F8651X
• Power Supply Modules: F8621, F8622
• Communication Modules: F8670, F8671, F8672, F8673
• Digital Input DI Modules: F6202, F6203
• Digital Output DO Modules: F6204, F6205
• Analog Input AI Modules: F6214, F6215
• Analog Output AO Module: F6217
• Base / Backplane Components: F7101, F7102, F7103

Note: All items above belong to the legacy H41q/H51q HIQuad hardware family. No brand‑new modules are produced by OEM; units circulating on market are surplus stock spares only.

1.2 Supporting Software Status

The dedicated software for legacy HIQuad is ELOP‑II Factory. Outdated with fixed architecture, it receives no further version iterations, feature updates or technical upgrades from OEM. It only supports basic configuration and maintenance for old installed systems, cannot meet functional requirements of new‑generation safety systems, and offers no subsequent optimization or compliance updates.

1.3 Usage Rules

• H41q/H51q full series shall not be selected for any new‑build or expansion industrial projects;
• Only existing commissioned plants are eligible for limited OEM maintenance services; no new units or spare‑part expansion support is provided;
• Upgrade and migration shall be initiated when systems suffer frequent failures, spare‑part shortages or non‑compliance against safety requirements.

2. Core Consensus for Migration of Existing Installations

Standardized migration schemes are established for operating legacy H41q/H51q HIQuad safety systems, balancing revamp cost, hardware reuse rate, system stability and compliance. Core principles: maximize hardware reuse, scenario‑oriented adaptation and unified upgrade standards.

• Optimal migration for existing plants: All revamp, expansion and upgrade projects for H41q/H51q plants shall migrate to the new‑generation HIQuad‑X safety system. It enables maximum reuse of existing I/O modules, field wiring and bases, greatly reduces construction cost and downtime, retains original control logic, and supports smooth migration of legacy installations.
• New large‑scale plant solution: For new safety systems in large‑scale chemical, petrochemical and high‑hazard process plants, directly adopt high‑end HIMax safety systems, delivering high reliability, full redundancy and high computing power for safety control.

3. Ultimate Selection Criteria for Full HIMA Safety Product Portfolio

Standardized selection rules for HIMA safety products are defined based on plant scale, safety integrity level, installation conditions and functional demands, covering new‑build, revamp and special safety scenarios. Can be used as reference for project selection, solution review and equipment approval.

3.1 Selection for Large‑Scale High‑Hazard Plant Scenarios

Recommended Product: HIMax. Applicable Scenarios: All new‑build large‑scale high‑hazard process plants, mainly for ESD emergency shutdown, F&G fire & gas detection and HIPPS high‑integrity pressure protection systems. Advantages: High computing performance, complete redundant architecture and superior fault tolerance. Supports complex safety logic for large‑scale plants with massive I/O points, meets long‑term stable operation and strict compliance requirements, and is the preferred solution for large new‑build projects.

3.2 Selection for Revamp & Upgrade of Legacy Plants

Recommended Product: HIQuad‑X. Applicable Scenarios: Revamp, expansion, fault‑driven upgrade and system replacement for existing H41q/H51q HIQuad installations. Key Values: Perfect compatibility with legacy architecture; maximum reuse of original I/O modules and field cables without massive disassembly work. Equipped with updated continuously‑iterated configuration software, solving pain points of obsolete ELOP‑II Factory, enabling smooth and cost‑effective upgrade of legacy systems.

3.3 Selection for Distributed Small‑I/O Fast‑Response Safety Scenarios

Recommended Product: HIMatrix F. Applicable Scenarios: Distributed process points, local on‑site installation, small I/O quantity and fast‑response medium‑and‑small‑scale safety protection. Features: Compact footprint, flexible deployment, fast response and cost‑effective performance. Central cabinet deployment is not required, suitable for independent protection of distributed small‑scale safety control points on site.

3.4 Selection for SIL 4 Highest‑Level Fixed‑Logic High‑Hazard Protection

Recommended Product: Planar4. Applicable Scenarios: High‑hazard equipment protection requiring SIL 4 highest safety integrity level with fixed‑logic control, for zero‑fault‑tolerance critical process nodes. Core Advantages: Designed for ultra‑high safety‑level conditions. Fixed‑logic architecture delivers outstanding stability, top‑tier fault tolerance and compliance for ultimate protection of critical high‑hazard equipment.

3.5 Selection for Embedded Safety Development for Third‑Party Devices

Recommended Product: HICore1. Applicable Scenarios: Third‑party device integration, custom embedded safety function development and secondary development of non‑standard safety control logic. Values: High openness and compatibility. Quick interface with various third‑party industrial control devices, supports custom safety programming to satisfy non‑standard and personalized industrial safety control revamp demands.

4. Selection Red Lines & Compliance Prohibitions (Critical Reminder)

To guarantee project compliance, equipment stability and sustainable after‑sales maintenance, industry‑wide prohibitions shall be strictly followed for all projects:

• Absolute prohibition: H41q/H51q (legacy HIQuad) discontinued series shall never be selected for any new‑build, expansion or revamp project. Avoid deploying obsolete end‑of‑life hardware without OEM support or further software iteration.
• O‑M baseline for existing installations: Only basic maintenance is allowed for commissioned legacy units. Hardware expansion and software upgrade are forbidden. Replace with HIQuad‑X when service life expires or frequent failures occur.
• Scenario‑matching baseline: Match products strictly to application scenarios. Avoid deploying small‑scale systems for large plants or general‑grade systems for high‑SIL applications. Ensure safety integrity level fully matches process conditions.

5. Quick Reference Selection Table