Westinghouse Numa-Logic PLC Family
The Westinghouse Numa-Logic range was a family of programmable logic controllers (PLCs) developed by Westinghouse for industrial automation and machine control applications. The product range included controllers such as the PC-700, PC-900, PC-1100, PC-1200, PC-1250, PC-1500, and PC-1700.
Numa-Logic controllers were microprocessor-based systems designed to perform industrial control functions using programmable logic rather than hardwired relay logic.
PC-700
The PC-700 supported up to 256 digital I/O, 32 analog I/O, and up to 8K of memory. Local and remote I/O configurations were supported. Documentation places the PC-700 product lifespan between 1980 and 1998.
PC-900
The PC-900 supported up to 128 digital I/O, 16 analog I/O, and up to 3.5K of memory. Like the PC-700, it supported both local and remote I/O systems. Documentation places the PC-900 product lifespan between 1981 and 1998.
PC-1100, PC-1200 and PC-1250
The PC-1100, PC-1200, and PC-1250 formed a higher-end Numa-Logic controller family. These systems included built-in LAN capabilities, PID control functions, and supported up to 16K of memory. Documentation places these models in production from 1982 through 1998.
Programming
The PC-700, PC-900, PC-1100, PC-1200, and PC-1250 shared a common programming language and software environment. Programs could be transferred between controller models provided the program did not exceed the memory or I/O limitations of the target controller.
Programming was performed using Westinghouse software packages including NLSW-783, NLSW-783U, NLSW-784, and NLSW-786. These packages provided ladder logic programming functions and, depending on the version, offline utilities and program documentation features.
Westinghouse also offered an add-on utility known as WHO (Westinghouse Help Outline) which provided online programming, diagnostics, PLC monitoring, communications, and remote access functions.
Communications
Numa-Logic PLCs used serial communications interfaces and could be connected to programming terminals and computers using EIA-232 serial connections. Later systems also supported networking and LAN-based communications.
Ownership History
The Numa-Logic PLC family was originally developed by Westinghouse. The product line later became part of Eaton Cutler-Hammer following Eaton’s acquisition of Westinghouse industrial control products in the 1990s. Legacy Numa-Logic support was subsequently transferred to Advanced Technology Services (ATS).