An On-Line Focal-12 Program for Auto-Analyzers

Summary

This document provides the technical documentation and user manual for a data acquisition and reduction program designed for auto-analyzers, developed by the U.S. Food and Drug Administration. The system utilizes a PDP-12A computer to process signals from a spectrophotometer recorder via an analog-to-digital (A/D) converter.

Key features and operation include:

• System Components: The setup includes the PDP-12A computer, a custom hardware interface using a retransmitting slidewire on the recorder, and software written in a modified version of FOCAL-12.
• Program Structure: The software consists of four segments (%ONITA1 through %ONITA4) stored on magnetic tape. These manage initialization, real-time data collection/peak detection, and calculation of results.
• Data Processing: The program detects peaks based on first derivatives, performs baseline correction using a linear fit between initial and final baseline points, and calculates "percent declared" values based on user-provided standard concentrations and dilution factors.
• User Interaction: Operators initialize the system via a teletype interface and control data collection using a sense switch on the computer console. The program provides flexibility for verification and recalculation of peak identities.
• System Requirements: The system requires at least four standards per run, and storage is limited to 70 readings. It is noted as a versatile, low-cost solution intended for projects of limited duration or as an interim measure during the development of more advanced systems.