Product Overview

The 901F-2562​ is the main control board — the central processing unit — of the CTI 2500 Series Classic Programmable Automation Controller, manufactured by Control Technology Inc. (CTI) of Knoxville, Tennessee, USA. As the computational core of the 2500 Series rack, the 901F-2562​ executes all logic operations, sequential control, PID loop management, communication scheduling, and system supervision. It is the component that gives the entire rack its identity as a controller rather than a collection of I/O modules.

The defining purpose of the 901F-2562​ is continuity. When Siemens discontinued the SIMATIC 505 family of controllers, a large installed base of 545 and 555 CPUs was left technically sound but commercially unsupported. The 901F-2562​ was engineered specifically to occupy the same rack and slot, run compatible firmware, and work with the existing I/O base, field terminations, and program structure. The result is a controller replacement that does not require redrawing wiring schedules, revalidating the field side, or retraining operators on new logic conventions.

In technical terms, the 901F-2562​ is a single-width, rack-mounted module that draws power from the backplane. It combines a high-speed industrial-grade processor with 256 KB (and above) of user program memory, onboard RAM and Flash storage, a battery-backed real-time clock, and watchdog supervision. Its I/O capacity reaches up to 2048 discrete points and 1024 analog points, making it suitable for both substantial process control applications and complex discrete manufacturing lines.