SCHIELE SCHRACK Series Modules | 2.423.430.00 Digital Input Module

Technical Dossier

Product Details And Specifications

SCHIELE SCHRACK Series: Comprehensive Module Range and Technical Overview

The SCHIELE SCHRACK automation platform is a modular distributed control system (DCS) and programmable logic controller (PLC) architecture developed by SCHIELE Systemtechnik GmbH, Germany. Deployed extensively across heavy industrial sectors — including petrochemical refineries, chemical processing plants, nuclear auxiliary systems, and offshore oil & gas facilities — the SCHRACK series established a significant installed base throughout Europe and Asia-Pacific from the 1980s through the 2000s. Its backplane-based modular architecture, deterministic scan cycle, and robust EMC shielding made it a preferred platform for safety-critical continuous process environments where mean time between failures (MTBF) requirements exceed 100,000 hours. Many facilities operating SCHIELE SCHRACK infrastructure continue to run original hardware under long-term maintenance contracts, making access to genuine spare modules a critical operational requirement.

The Evolution of SCHRACK Architecture

The SCHIELE SCHRACK platform evolved through three principal hardware generations. The first generation (circa 1982–1991) introduced the foundational rack-and-backplane topology with parallel bus communication, supporting basic digital I/O and analog signal conditioning at 4–20 mA. Module addressing was hardware-configured via DIP switches, and the CPU modules of this era operated on proprietary instruction sets with cycle times in the 10–50 ms range.

The second generation (circa 1991–2001) introduced enhanced serial backplane communication, expanded the I/O address space, and added support for PROFIBUS-DP fieldbus adapters. CPU processing speeds improved significantly, and redundant power supply configurations became standard for Tier-1 installations. Analog modules in this generation supported 12-bit and 16-bit resolution, enabling finer process variable control.

The third and final generation (circa 2001–2010) integrated Ethernet-based communication options, expanded diagnostic capabilities with module-level fault reporting, and introduced hot-swap capability on select I/O modules. Production of new SCHRACK hardware was formally discontinued by approximately 2012, placing the entire series in end-of-life (EOL) status. All currently available units are sourced from certified surplus inventory, decommissioned plant equipment, or authorized repair channels. For facilities maintaining SCHRACK-based control systems, lifecycle extension strategies — including cross-reference to compatible third-party replacements and board-level repair — are the primary continuity options.

SCHIELE SCHRACK Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly traded modules within the SCHIELE SCHRACK platform. Each entry reflects the module's primary functional classification and signal specification.

Digital Input (DI) Modules

• 2.423.430.00: 16-channel 24 VDC digital input module, sink/source configurable, backplane bus interface
• 2.423.431.00: 32-channel 24 VDC digital input module, high-density rack format, LED status per channel
• 2.423.432.00: 16-channel 120 VAC digital input module, optically isolated, DIN rail compatible
• 2.423.433.00: 8-channel 230 VAC digital input module, surge-protected inputs, CE marked

Digital Output (DO) Modules

• 2.423.440.00: 16-channel 24 VDC transistor output module, 0.5 A per channel, short-circuit protected
• 2.423.441.00: 8-channel relay output module, 2 A / 250 VAC per contact, Form C contacts
• 2.423.442.00: 16-channel relay output module, 1 A / 24 VDC, plug-in terminal block

Analog Input (AI) Modules

• 2.423.410.00: 8-channel 4–20 mA analog input module, 12-bit resolution, differential inputs
• 2.423.411.00: 8-channel ±10 V analog input module, 16-bit resolution, programmable gain
• 2.423.412.00: 4-channel thermocouple input module, types J/K/T/E/R/S/B, cold junction compensation
• 2.423.413.00: 4-channel RTD input module, PT100/PT1000, 3-wire and 4-wire configurations

Analog Output (AO) Modules

• 2.423.420.00: 4-channel 4–20 mA analog output module, 12-bit resolution, loop-powered option
• 2.423.421.00: 4-channel ±10 V analog output module, 16-bit resolution, simultaneous update

CPU / Controller Modules

• 2.423.100.00: Central processing unit module, IEC 61131-3 compliant, 256 KB program memory, RS-232/RS-485 ports
• 2.423.101.00: Enhanced CPU module, 1 MB program memory, integrated PROFIBUS-DP master port, real-time clock

Communication & Power Modules

• 2.423.200.00: PROFIBUS-DP slave adapter module, 12 Mbit/s, GSD file available
• 2.423.300.00: 24 VDC rack power supply module, 5 A output, wide-range AC input 85–264 VAC
• 2.423.301.00: Redundant power supply module, hot-swap capable, fault relay output

Sourcing Hard-to-Find & Obsolete SCHIELE SCHRACK Parts

With the SCHRACK series in full end-of-life status since approximately 2012, OEM factory support and new production are no longer available. DriveKNMS maintains a dedicated inventory of tested SCHIELE SCHRACK modules sourced from decommissioned industrial sites, authorized surplus channels, and controlled disassembly of complete rack systems. This inventory supports facilities operating under long-term maintenance agreements where control system replacement is not economically or operationally feasible within the current planning horizon.

DriveKNMS provides the following lifecycle extension services for the SCHRACK platform: verified surplus module supply with full traceability documentation; board-level repair and component replacement for modules with repairable fault conditions; functional equivalence cross-referencing to identify compatible third-party substitutes where direct replacements are unavailable; and emergency same-day dispatch for critical process shutdown situations. All modules are individually tested against original SCHIELE factory specifications prior to dispatch.

Quality Control for the SCHIELE SCHRACK Range

SCHIELE SCHRACK modules present specific quality verification challenges due to their backplane bus architecture and the age profile of available surplus stock. DriveKNMS applies a structured test protocol to each module prior to release:

• Visual and mechanical inspection: PCB condition assessment, connector pin integrity check, capacitor ESR measurement on power rail filter stages
• Powered functional test: Each module is installed in a SCHIELE SCHRACK test rack and exercised through its full I/O channel range using calibrated signal sources and loads
• Bus communication verification: Backplane data and address bus integrity is confirmed via protocol analyzer; module responds correctly to CPU polling cycles
• Analog accuracy calibration: AI and AO modules are calibrated against NIST-traceable references; linearity, offset, and gain errors are measured and documented
• Burn-in cycle: Modules are operated at rated load for a minimum of 24 hours in a temperature-controlled environment to screen for early-life component failures
• Documentation package: Each shipped module includes a test report with channel-by-channel results, serial number, and technician sign-off