BAS-3512/3520 is a standalone programmable controller specially designed for building automation applications. Designed as a typical DDC (Direct Digital Controller), BAS-3512/3520 delivers various of onboard I/O including universal input, analog output, digital input and digital output, providing flexible options to satisfy versatile application requirements. It also features powerful BASPro programming tool for engineers to quickly develop their application. BASPro delivers many function blocks suitable for BA application, such as scheduler, HVAC calculation, sequential control, PID control, alarm, and event. Its compact size makes it an ideal solution to fulfill BA installation environment. The I/O expansion modules (BAS-3018, BAS-3024, BAS-3050 and BAS-3051) provide more I/O points and make the system a scalable solution.