CueServer's contact closure inputs are digital inputs into CueServer that can accept input from several sources. This article will help to explain some of the more technical details of the input ports and how to connect more advanced devices to the inputs.
Each contact closure input can accept an input voltage from -36V to +36V. With no load on the contact closure, it will float to around 3.3V (this is accomplished with a weak internal pull-up resistor). When the voltage drops to below 0.9V, the contact will be considered "closed". When the voltage rises above 2.3V, the contact will be considered "open".
It is easy to add a switch, pushbutton or relay to one of these inputs by wiring the switch between one of the inputs and one of the grounds. When the switch is open, the voltage floats up, causing CueServer to sense that the contact is open. When the switch closes, it shorts the input to ground (forcing it to near zero volts), causing CueServer to sense that the contact is closed.
Many other digital devices may be connected to CueServer's contact closure (digital input) ports. Any device that has a "pull-to-ground" output (such as a transistor output), can be wired directly to CueServer's inputs. Just make sure that the two devices' grounds are connected together (so that they share the same ground potential). Many devices such as security systems, automation systems, wireless receivers and even other CueServers' outputs can all be directly tied to CueServer's inputs.
It is also possible to connect some "analog" devices to CueServer's inputs. Our customers have attached photocells (for detecting ambient light levels) and wind-speed meters to CueServer's digital inputs. For these type of devices, one should expect CueServer to notice a transition from "open" to "closed" in the 0.9 to 2.3V threshold. As long as the connected device swings through this range at the desired sense point, then it can be attached to CueServer without any additional circuitry.
For additional information or applications assistance, please contact our Technical Support department.