Shimadzu PC-55N Analog-to-Digital Conversion Board (Requires CBM-20A System Controller)

Overview

The Shimadzu PC-55N Analog-to-Digital Conversion Board is a legacy hardware module designed for integration into Shimadzu’s early-generation liquid chromatography (LC) data acquisition systems. Specifically engineered to interface with the CBM-20A system controller, this board converts analog voltage signals—originating from detectors such as UV-Vis, fluorescence, or conductivity units—into high-fidelity digital data streams for real-time acquisition and processing by host software (e.g., CLASS-VP or earlier Shimadzu LC control platforms). Its architecture adheres to industry-standard signal conditioning practices of the 1990s–early 2000s, featuring 12-bit resolution, programmable gain amplification, and synchronized sampling triggered via the CBM-20A’s timing bus. As a discontinued OEM component, the PC-55N remains operationally critical for laboratories maintaining functional Shimadzu LC systems built around the CBM-20A platform—including models such as LC-6A, LC-8A, RF-535, and SPD-6A.

Key Features

• Native Shimadzu OEM design ensuring full electrical and firmware compatibility with CBM-20A-based LC systems
• High-stability analog front-end with low-noise operational amplifiers and precision reference voltage circuitry
• Hardware-level synchronization with CBM-20A’s system clock, minimizing timing jitter during peak detection and integration
• Support for dual-channel simultaneous acquisition (e.g., primary detector + auxiliary reference channel)
• Standard ISA-bus interface compatible with industrial PCs used in original Shimadzu LC workstations (e.g., IBM-compatible 486/Pentium-era systems)
• No driver installation required—recognized automatically by CLASS-VP v3.x and earlier versions when installed under CBM-20A control

Sample Compatibility & Compliance

The PC-55N does not process samples directly but serves as an essential signal digitization layer within regulated LC workflows. When deployed in validated environments, it supports analytical procedures compliant with ISO/IEC 17025:2017 (General requirements for the competence of testing and calibration laboratories) and ASTM E2500-13 (Standard Guide for Specification, Design, and Verification of Pharmaceutical and Biopharmaceutical Manufacturing Systems). While the board itself carries no CE marking or FDA 510(k) clearance—consistent with its status as a legacy internal subsystem—it maintains traceable performance consistency across installations when paired with calibrated detectors and maintained per Shimadzu’s original technical bulletins (e.g., TN-LC-017 Rev. B). Laboratories subject to GLP or GMP audits must document its use as part of the instrument’s configuration baseline and include it in periodic verification protocols (e.g., linearity check using certified step-voltage sources).

Software & Data Management

The PC-55N operates exclusively under Shimadzu’s proprietary CLASS-VP software suite (versions 3.2 through 5.0), where raw ADC values are mapped to chromatographic time domains using fixed sampling intervals (typically 0.1–1.0 s). Data output conforms to Shimadzu’s native .chd file format, supporting peak integration, retention time alignment, and quantitative reporting via external spreadsheet or LIMS interfaces. Though not natively compatible with modern Windows OS beyond Windows XP SP3, virtualized execution (e.g., VMware Workstation with Windows XP guest OS) enables continued data reprocessing and archival retrieval. Audit trail functionality is limited to software-level logging; for 21 CFR Part 11 compliance, supplemental electronic signature and change-control layers must be implemented at the CLASS-VP application level—not at the PC-55N hardware layer.

Applications

• Continued operation of aging Shimadzu LC systems in academic research labs conducting method transfer studies or historical data reanalysis
• Cost-effective replacement for failed ADC boards in quality control labs performing compendial assays (e.g., USP , EP 2.2.46)
• Reference instrumentation in metrology labs validating detector linearity and dynamic range using NIST-traceable standards
• Training environments for chromatography fundamentals, where hardware transparency aids student understanding of signal acquisition physics
• Backup spares inventory for pharmaceutical manufacturing sites retaining validated LC methods on legacy platforms

FAQ

Is the PC-55N compatible with CBM-10A or CBM-102 controllers?

No. The PC-55N requires the CBM-20A’s specific timing protocol and register map; it is incompatible with earlier CBM-10A or later CBM-102/103 controllers.
Does this board support USB or Ethernet connectivity?

No. It uses only the ISA bus interface and requires a compatible industrial PC with ISA slots and legacy BIOS support.
Can I calibrate the PC-55N independently of the detector?

No. Calibration is performed system-wide using detector-specific reference standards; the PC-55N contributes no adjustable offset or gain parameters outside CLASS-VP’s hardware abstraction layer.
Is firmware upgrade available for this board?

No. The PC-55N contains mask ROM firmware and is not field-upgradable.
What documentation accompanies the unit?

A scanned copy of Shimadzu’s original Technical Manual TN-LC-017 (English) and CBM-20A Interface Specification Rev. 2.1 is provided upon request.