At my day-job, we’ve recently started putting in the Telos VX Prime phone system. It gives us eight telephone hybrids, SIP-connectivity, and Livewire support. It’s a great little box, and surprisingly simple to get setup. This article explains how to disable the audible VSet phone ringtone in your studios whenever a microphone is turned on.

GPIO In the Telos VX Phone System

Every Studio in the VX allows you to setup GPIO Actions, and GPIO Indications.

  • GPIO Actions are things the VX does as a result of an external trigger (logic coming INTO the VX).
  • GPIO Indications are things another device does as a result of a change in the VX (logic going OUT of the VX).

The actions currently available in the Telos VX are:

  • Take next call
  • Take next ringing line
  • Hold all calls
  • Drop all calls
  • Enable Block All
  • Disable Block All
  • Toggle Block All
  • Toggle Auto Answer & Hold
  • Mute Ringer
  • Change show to “Show Name”

The indications currently available in the Telos VX are:

  • Next call available
  • Line ringing
  • Line ringing (‘Busy All’)
  • Line ringing (non-‘Busy All’)
  • Call can be held
  • Call can be dropped
  • Block All enabled
  • Auto Answer & Hold enabled
  • Ringer muted
  • Delay Dump
  • Current show is “Show Name“

GPIO Setup to Mute the Ringer

We’re going to take the GPO from an Axia Console (Element, Fusion, iQ, or Radius – doesn’t matter), and use it to mute the audible ringer on that studio’s VSet.

First, we need to find the GPIO stream number for your console’s Control Room Monitor (CR Monitor) GPIO.

In the Element and Fusion consoles, the CR Monitor GPIO is console-wide, and has the same number as your CR Monitor Audio Stream. When you login to your Axia Studio Engine, go to the “Prog and mon out” screen, and find the channel number next to “CR Monitor”.

On a Axia QOR-based console (such as the iQ and Radius), CR Monitor GPIO is set per-show. Go to your show profile configuration, and look for the “Logic Port” below the the “CR Monitor” column. The channel number here is what you’re looking for.


Now we have our GPIO Channel Number for the CR Monitor output in our studios, we need to go back to the Telos VX Studio configuration page.

Create a new GPIO Action “Mute Ringer”, and enter in your CR Monitor Channel Number from your Engine/QOR. Select “Pin 1” and type “To GPIO”. We select Pin 1, because Axia always provides a solid closure on this pin whenever the in-studio mics are turned on (it’s commonly used for an on-air light relay).

This screenshot shows the basic setup with two GPIO Actions:

A quick work on GPIO Directionality… In Axia land, an input on one device is an output on another – a system that make sense in the analog works but can be a little confusing in the digital world. In the case of the VX, “To GPIO” means it’s an output from another system and an input to the VX. Likewise, “From GPIO” means it’s an output from the VX and an input to another device. It makes sense, but isn’t immediately obvious. You’d almost always want your Actions to be “To GPIO” and your Indications to be “From GPIO”.


That’s pretty much all you need to do. When you save the changes, any Talent VSets linked to this Studio in your VX Engine will be muted at the same time as your control room speakers.