Contact Closures and Digital Outputs

CueServer 2 provides up to eight low-voltage contact-closure inputs and up to eight low-voltage digital outputs. Contact closures are designed for connecting switches, buttons, motion detectors, or other devices that make an electrical connection between two conductors. Digital outputs are designed for connecting LED indicators, small relays, buzzers, pilot lights, and most anything that can be powered from a small DC voltage.

To better understand Contact Closure and Digital Outputs, we will cover a rather simple and common scenario below. You can also learn more about the specifics for CueServer 2 Contact Closures here or Digital Outputs here.

The Scenario

You have a momentary switch that you would like to have instruct CueServer to run a Cue when pressed. You also have an LED to be used as an indicator which should be illuminated when the button is pressed.

The Breakdown

For this example, we will be using Contact Closure 1 and Output 1. Our momentary switch will be Normally-Closed and our LED will not have a resistor built-in.

To set up our momentary switch (and LED), we will need to create some rules for contact 1 to turn on output 1 whenever the contact is closed as well as execute our cue. We will also need to create a rule to turn off the momentary switch LED once the contact is opened (no longer depressed).

For the hardware, we need to connect our switch to contact 1 and our led to output 1. For our LED, because it does not have a built-in resistor, we must add a resistor between the CueServer and LED. You can skip ahead to the hardware setup here.

We'll cover this a bit more in-depth below.

The Walkthrough

In order to tell CueServer to take any action upon a contact state-change, we must create a rule. Given we're using a normally-open momentary switch, our first rule will be to set Output 1 to ON whenever the contact is closed.

In effect, whenever the momentary switch is closed, the circuit will be closed. When CueServer detects the closed state of the contact, this rule will automatically act to short output 1 to ground, turning it on. In this case, our LED (connected to output) will illuminate.




Now that our output is set to automatically turn on when the contact is closed, we need to add an additional action to our Is Closed condition by hovering to the right of our last condition and clicking on +THEN.

Next, we add our second condition to Execute Cue 1. This tells the CueServer to both turn on Output 1 and Execute Cue 1 whenever Contact 1 changes to a closed state.



We've set up our rules for the Is Closed condition. We now need to add the opposite for the Is Opened condition. By adding the second condition, we are instructing the CueServer to turn the output back off when the contact is re-opened (switch is let go).

Since our cue will be launched by the closure of the contact (button press) and end when it has finished, we don't need to add any actions for our Cue on the Is Opened condition.


The Hardware Setup


To set up our momentary switch (Normally-Open), we need to connect our switch leads. One of the leads will go to the CueServer Ground input, the second lead will go to the CueServer Contact Closure.

Once connected (see schematic), whenever the momentary switch is depressed, the Ground will be shorted to the Contact, in turn, closing the contact.


Next, to connect our LED, we need to wire our +5V output from CueServer to our resistor, then, from the resistor to the anode side of our LED.

The Cathode side of our LED will be wired directly to our Digital Output.

Once the LED is connected (see schematic), given the rules we programmed earlier, whenever the momentary switch is depressed, the Ground will be shorted to the Contact which will close the contact closure and turn on output 1, illuminating the LED.


The full schematic for hardware setup



Have a Tip or Trick you would like to see? Let us know!

The rules we established for contact 1 will direct CueServer to execute Cue 1 and turn on Digital Output 1 whenever contact 1 is closed.

The connection we made of our momentary switch will transfer the floating ~3v output to the contact closure 1 input whenever the switch is depressed.

When output 1 is turned on, the output will short the connection from our cathode to ground, allowing current to flow from our +5V output, through the resistor, into the anode and illuminating the LED.

Now that you've learned the concept of contact closures and digital outputs, check out how to use a relay and motion detector with CueServer.