The SENTRY™ LINK-IT 2 is a cost effective but versatile IoT (Internet of Things) solution for various remote automation projects. Multiple users WEB and APP controlled. SMS control is available as well. It provides one digital Input (configurable by polarity of triggering) and one relay Output (active state settable to Low or High plus NO and NC free potential contacts). here is an option to logically “link” the input to the output i.e. the certain state of the input automatically sets a predefined state of the output.