The AS3035 (wall-mounted) cooling tower controller is designed for fully automatic monitoring and controlling of cooling tower systems. By means of an optional plug-in card IF2030, the control options can be further extended with one programmable input and two programmable outputs. Via plug-in card IF2030 an inlet valve can be controlled to add water to the system. The inlet valve is controlled by a level switch that can also be connected to the plug-in card. The controller is equipped with a conductivity meter.