Siemens QLSAMBAN

Technical Dossier

Product Details And Specifications

Siemens QUADLOG Series Technical Notes

The Siemens QUADLOG safety system is a dedicated Safety Instrumented System (SIS) platform engineered for high-demand process industries including petroleum refining, chemical processing, nuclear power generation, and offshore oil & gas production. QUADLOG is designed to meet IEC 61508 SIL 2 and SIL 3 requirements, providing redundant, fault-tolerant control architectures for Emergency Shutdown (ESD), Fire & Gas (F&G), and Burner Management Systems (BMS). Installed across thousands of critical process units globally, the QUADLOG platform remains one of the most widely referenced legacy SIS architectures in long-term plant maintenance inventories.

The Evolution of QUADLOG Architecture

QUADLOG was developed by Moore Products Co., which was subsequently acquired by Siemens. The platform was positioned as a quad-redundant safety controller — its name directly referencing its four-channel voting logic architecture (4oo4D). Early deployments in the 1990s established QUADLOG as a preferred SIS solution for North American and European refineries operating under ISA S84.01 and early IEC 61511 frameworks.

As the QUADLOG platform has entered its end-of-life and obsolescence phase, Siemens has directed new SIS projects toward the SIMATIC Safety Integrated platform (S7-300F, S7-400F/FH, S7-1500F). However, the installed base of QUADLOG systems in brownfield facilities remains substantial, creating sustained demand for original spare parts, refurbished modules, and lifecycle extension support.

QUADLOG Full Catalog & Functionalities (SKU List)

The following SKUs represent the core QUADLOG module range. All models listed are verified components of the Siemens QUADLOG SIS platform.

Safety Application Modules (SAM / Logic Solvers)

• QLSAMBAN: QUADLOG Safety Application Module, standard BAN variant, central logic solver for SIL 2/3 ESD applications
• QLSAM: QUADLOG Safety Application Module, base version, quad-redundant voting logic processor
• QLSAMR: QUADLOG SAM replacement/repair revision, compatible with standard QUADLOG backplane

Digital Input Modules (DI)

• QLDIB16: QUADLOG 16-channel 24 VDC digital input module, SIL 2 rated, field device monitoring
• QLDIB32: QUADLOG 32-channel digital input module, high-density field wiring, process shutdown inputs
• QLDI24V: QUADLOG digital input, 24 VDC, single-ended, for discrete sensor interfacing

Digital Output Modules (DO)

• QLDOB16: QUADLOG 16-channel digital output module, relay-driven, ESD valve and actuator control
• QLDOB8R: QUADLOG 8-channel relay output module, high-current switching for solenoid valves

Analog Input Modules (AI)

• QLAIB8: QUADLOG 8-channel analog input, 4–20 mA HART-compatible, transmitter signal acquisition
• QLAIB16: QUADLOG 16-channel analog input module, process variable monitoring for SIS loops

Analog Output Modules (AO)

• QLAOB4: QUADLOG 4-channel analog output, 4–20 mA, positioner and control element interface

Power Supply Modules (PS)

• QLPS24: QUADLOG 24 VDC redundant power supply module, backplane bus power distribution
• QLPSR: QUADLOG power supply redundancy module, hot-swap capable, no-break switchover

Communication & Network Modules

• QLCOMB: QUADLOG communication bridge module, Modbus RTU master/slave interface to DCS/SCADA
• QLPROFIB: QUADLOG PROFIBUS DP adapter, integration with Siemens SIMATIC DCS environments
• QLENET: QUADLOG Ethernet communication module, OPC server connectivity for historian integration

Chassis & Backplane

• QLCHAS8: QUADLOG 8-slot chassis, standard rack for SAM and I/O module mounting
• QLCHAS16: QUADLOG 16-slot expanded chassis, high I/O count process unit configurations

Quality Control for the QUADLOG Range

QUADLOG modules present specific testing challenges due to their proprietary quad-redundant backplane bus architecture and internal voting logic. DriveKNMS applies the following QC procedures to all QUADLOG inventory:

• Backplane bus continuity and signal integrity verification using QUADLOG-compatible test chassis
• SAM module logic solver functional test: application program load, watchdog timer validation, and diagnostic self-test cycle completion
• I/O module channel-by-channel verification: input threshold accuracy (±0.1% FS for analog), output switching confirmation for relay and solid-state channels
• Communication module protocol handshake testing: Modbus RTU frame integrity, PROFIBUS DP token ring participation
• Visual inspection: capacitor condition, connector pin integrity, conformal coating assessment, firmware revision labeling
• Burn-in cycle: 48-hour powered operation under simulated load prior to shipment