GPIO
General Purpose Input Output (GPIO) has been a common function in radio studios for many years. Though AoIP has changed the way in which components interface with one another, logic states between gear remains widely depending on this legacy method of wiring.
From the beginning, Axia has endeavored to make the process of configuring GPIO as plug-and-play as possible, and the strategy used to achieve this has been to define behavior through the use of profiles. Each Source Profile (as outlined in Chapter 3) defines how the 5 GPI, 5 GPO, and 15 pin GPIO ports behave based upon how each is expected to be employed in a typical studio. Information about each Source Profile plus tables for GPIO ID and pin-outs are provided below.
Source Profiles
Source profiles include:
Line Input – Used for any general audio source.
Computer Player – Similar to Line Input, but with a different logic control commonly found with PC-based automation systems. For example, pressing the “On” button while the source is already in the “on” state triggers the next event in the automation.
Phone – Defines the source as a hybrid or broadcast phone system input. Single line phone hybrids commonly want the line to be seized when a state is changed on the console, such as when the channel is turned on or set to a preview state. A summed mono mix-minus is automatically created for the source, and controls for Telos products will be available.
Codec – Links to remote codecs often require a GPIO to trigger IFB communication and a dual mono mix-minus for the source consisting of one PA feed (right channel) and one talent feed with talkback (left channel).
Operator Microphone – This is the board op’s mic which often requires different GPIO functions than other studio microphones.
CR Producer Microphone – The in-studio producer’s mic may not have access to the console but often requires the same controls as the operator.
CR Guest Microphone – Used for any other mic in the control room.
Studio Guest Microphone – Similar to the CR Guest Microphone, but with different monitor muting requirements.
External Microphone – Used for any mic located outside of the CR or studio, this functions like a Guest microphone but without any muting logic.
Studio Feed – Typically a source that receives a backfeed and generates an IFB backfeed in return. This is intended for an external studio source for which you wish to create a talkback channel.
Record Mode – Provides GPIO control of the various Record button functions
External Timer Control – Provides GPIO control of the count-up timer.
V-Mixer – Controls the Vmixer “On” states.
Show Profile – Allows GPIO control and status of Show Profiles.
Input, Output, and Pin Numbers
The following tables show pin numbers as they would appear on a Telos Alliance xNode with 15-pin GPIO ports. Common pins that are not profile-specific are as follows and are not listed in the individual tables:
Pin 7 – GPO Common pin, typically tied to GND by application
Pin 8 – GPIO port GND
Pin 9 – 5vDC supply
Pin 10 – GPI common pin, typically tied to 5vDC by application
Line Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel and triggers START pulse |
GPI 2 | OFF Command | 12 | Momentary turns OFF console channel and triggers STOP pulse |
GPI 3 | PREVIEW Command | 13 | Active = PREVIEW ON Not Active = PREVIEW OFF |
GPI 4 | RESET Command | 14 | Momentary turns OFF channel w/o generating a GPO STOP pulse |
GPI 5 | READY Command | 15 | Latch to indicated READY (OFF button illuminated) for profiles defined with the READY enable |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state |
GPO 2 | OFF lamp | 2 | Latching during OFF state and READY command if enabled |
GPO 3 | PREVIEW lamp | 3 | Latching during PREVIEW state |
GPO 4 | START pulse | 4 | Momentary at transition to ON |
GPO 5 | STOP pulse | 5 | Momentary at transition to OFF |
Computer Player Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel and triggers START pulse |
GPI 2 | OFF Command | 12 | Momentary turns OFF console channel and triggers STOP pulse |
GPI 3 | PREVIEW Command | 13 | Active = PREVIEW ON Not Active = PREVIEW OFF |
GPI 4 | Not used | 14 | |
GPI 5 | READY Command | 15 | Latch to indicated READY (OFF button illuminated) for profiles defined with the READY enable |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | NEXT pulse | 1 | Momentary when ON button pressed and already in the ON state |
GPO 2 | OFF lamp | 2 | Latching during OFF state and READY command if enabled |
GPO 3 | PREVIEW lamp | 3 | Latching during PREVIEW state |
GPO 4 | START pulse | 4 | Momentary at transition to ON |
GPO 5 | STOP pulse | 5 | Momentary at transition to OFF |
Phone Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel and triggers START pulse if ON is configured to answer hybrid |
GPI 2 | OFF Command | 12 | Momentary turns OFF console channel and triggers STOP pulse if ON is configured to answer hybrid |
GPI 3 | PREVIEW Command | 13 | Active = PREVIEW ON Not Active = PREVIEW OFF |
GPI 4 | Not used | 14 | |
GPI 5 | READY Command | 15 | Latch to indicated READY (OFF button illuminated) for profiles defined with the READY enable. Can be used to provide ring indication. |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state |
GPO 2 | OFF lamp | 2 | Latching during OFF state and READY command if enabled |
GPO 3 | PREVIEW lamp | 3 | Latching during PREVIEW state |
GPO 4 | START pulse | 4 | Momentary to seize line based on hybrid control configuration |
GPO 5 | STOP pulse | 5 | Momentary to release line based on hybrid control configuration |
Codec Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel |
GPI 2 | OFF Command | 12 | Momentary turns OFF console channel |
GPI 3 | PREVIEW Command | 13 | Active = Routes channel audio to Preview and mutes channel |
GPI 4 | Not used | 14 | Mutes console channel |
GPI 5 | READY Command | 15 | Active = Initiates Talkback to Source from Operator Mic or Ext Talk |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state |
GPO 2 | OFF lamp | 2 | Latching during OFF state and READY command if enabled |
GPO 3 | TALK TO CR lamp | 3 | Latching during active TALK TO CR state |
GPO 4 | MUTE lamp | 4 | Latching during active MUTE state |
GPO 5 | TALKBACK lamp | 5 | Latching during an active TALKBACK |
Operator Microphone Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel |
GPI 2 | OFF Command | 12 | Momentary turns OFF console |
GPI 3 | TALK TO STUDIO Command | 13 | Active = TALK TO STUDIO and will MUTE channel |
GPI 4 | MUTE command | 14 | Mutes channel console |
GPI 5 | TALK to source in Preview Command | 15 | Active = Initiates Talkback to channels that are in PREVIEW from Operator Mic and will MUTE channel |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state unless TALK or MUTE are active |
GPO 2 | OFF lamp | 2 | Latching during OFF state |
GPO 3 | TALK TO STUDIO lamp | 3 | Latching during active TALK TO STUDIO state |
GPO 4 | MUTE lamp | 4 | Latching during active MUTE state |
GPO 5 | TALK to source in Preview lamp | 5 | Latching during an active TALK |
CR Producer Microphone Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel |
GPI 2 | OFF Command | 12 | Momentary turns OFF console |
GPI 3 | TALK TO STUDIO Command | 13 | Active = TALK TO STUDIO and will MUTE channel |
GPI 4 | MUTE command | 14 | Mutes channel console |
GPI 5 | TALK to source in Preview Command | 15 | Active = Initiates Talkback to channels that are in PREVIEW from Producer Mic and will MUTE channel |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state unless TALK or MUTE are active |
GPO 2 | OFF lamp | 2 | Latching during OFF state |
GPO 3 | TALK TO STUDIO lamp | 3 | Latching during active TALK TO STUDIO state |
GPO 4 | MUTE lamp | 4 | Latching during active MUTE state |
GPO 5 | TALK to source in Preview lamp | 5 | Latching during an active TALK |
CR Guest Microphone Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel |
GPI 2 | OFF Command | 12 | Momentary turns OFF console |
GPI 3 | TALK TO CR Command | 13 | Active = TALK TO CR (Preview channel) and will MUTE channel |
GPI 4 | MUTE command | 14 | Mutes channel console |
GPI 5 | Not used | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state unless TALK or MUTE are active |
GPO 2 | OFF lamp | 2 | Latching during OFF state |
GPO 3 | TALK TO CR lamp | 3 | Latching during active TALK TO CR state |
GPO 4 | MUTE lamp | 4 | Latching during active MUTE state |
GPO 5 | Not used | 5 |
Studio Guest Microphone Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel |
GPI 2 | OFF Command | 12 | Momentary turns OFF console |
GPI 3 | TALK TO CR Command | 13 | Active = TALK TO CR (Preview channel) and will MUTE channel |
GPI 4 | MUTE command | 14 | Mutes channel console |
GPI 5 | Not used | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state unless TALK or MUTE are active |
GPO 2 | OFF lamp | 2 | Latching during OFF state |
GPO 3 | TALK TO CR lamp | 3 | Latching during active TALK TO CR state |
GPO 4 | MUTE lamp | 4 | Latching during active MUTE state |
GPO 5 | Not used | 5 |
External Microphone Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel |
GPI 2 | OFF Command | 12 | Momentary turns OFF console |
GPI 3 | TALK TO CR Command | 13 | Active = TALK TO CR (Preview channel) and will MUTE channel |
GPI 4 | MUTE command | 14 | Mutes channel console |
GPI 5 | Not used | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state unless TALK or MUTE are active |
GPO 2 | OFF lamp | 2 | Latching during OFF state |
GPO 3 | TALK TO CR lamp | 3 | Latching during active TALK TO CR state |
GPO 4 | MUTE lamp | 4 | Latching during active MUTE state |
GPO 5 | Not used | 5 |
Studio Feed Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | ON Command | 11 | Momentary turns ON console channel |
GPI 2 | OFF Command | 12 | Momentary turns OFF console |
GPI 3 | TALK TO CR Command | 13 | Active = TALK TO CR (Preview channel) and will MUTE channel |
GPI 4 | MUTE command | 14 | Mutes channel console |
GPI 5 | Not used | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | ON lamp | 1 | Latching during ON state unless TALK or MUTE are active |
GPO 2 | OFF lamp | 2 | Latching during OFF state |
GPO 3 | TALK TO CR lamp | 3 | Latching during active TALK TO CR state |
GPO 4 | MUTE lamp | 4 | Latching during active MUTE state |
GPO 5 | Not used | 5 |
Control Room Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | MUTE CR Command | 11 | Mutes Preview and Monitors when active |
GPI 2 | DIM Command | 12 | Dims Monitors when active |
GPI 3 | EXT Preview Command | 13 | Routes External Preview defined in Show Profile to Preview |
GPI 4 | TALK TO EXT Command | 14 | Route Operator Mic or Ext Talk source as defined in Show Profile to Talk to External output |
GPI 5 | Not used | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | MUTE lamp, ON AIR lamp | 1 | Latching during Studio MUTE state |
GPO 2 | DIM lamp | 2 | Latching during DIM state |
GPO 3 | START/RESET lamp | 3 | Momentary indication of Timer change state |
GPO 4 | Not used | 4 | |
GPO 5 | TALK TO STUDIO lamp | 5 | Latching during an active TALK TO STUDIO |
Record (Enable) Mode Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | Not used | 11 | |
GPI 2 | Not used | 12 | |
GPI 3 | Not used | 13 | |
GPI 4 | Not used | 14 | |
GPI 5 | Not used | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | RECORD ACTIVE lamp | 1 | Latching while in Record mode |
GPO 2 | RECORD NOT ACTIVE | 2 | Latching while Record mode is off |
GPO 3 | Not used | 3 | |
GPO 4 | RECORD pulse | 4 | Momentary when entering Record mode |
GPO 5 | STOP pulse | 5 | Momentary when exiting Record mode |
External Timer Control Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | START command | 11 | Momentary starts timer |
GPI 2 | STOP command | 12 | Momentary stops timer |
GPI 3 | RESET command | 13 | Momentary resets timer |
GPI 4 | FREEZE command | 14 | Latching freezes timer view |
GPI 5 | Not used | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | START lamp | 1 | Momentary at timer start |
GPO 2 | STOP lamp | 2 | Momentary at timer stop |
GPO 3 | RESET lamp | 3 | Momentary at timer reset |
GPO 4 | FREEZE lamp | 4 | Active during freeze state |
GPO 5 | Not used | 5 |
V-Mixer Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | In 1 ON command | 11 | Normal: Latch to turn ON Toggle: Momentary for ON/OFF Radio: Last momentary is ON, all others OFF |
GPI 2 | In 2 ON command | 12 | |
GPI 3 | In 3 ON command | 13 | |
GPI 4 | In 4 ON command | 14 | |
GPI 5 | In 5 ON command | 15 |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | In 1 ON lamp | 1 | Active when ON |
GPO 2 | In 2 ON lamp | 2 | Active when ON |
GPO 3 | In 3 ON lamp | 3 | Active when ON |
GPO 4 | In 4 ON lamp | 4 | Active when ON |
GPO 5 | In 5 ON lamp | 5 | Active when ON |
Show Profile GPIO Table
Inputs (GPI)
ID | Name | Pin | Notes |
GPI 1 | None command | 11 | Changes to blank profile |
GPI 2 | Profile A command | 12 | Changes to A profile |
GPI 3 | Profile B command | 13 | Changes to B profile |
GPI 4 | Profile C command | 14 | Changes to C profile |
GPI 5 | Profile D command | 15 | Changes to D profile |
Outputs (GPO)
ID | Name | Pin | Notes |
GPO 1 | Profile None lamp | 1 | Active when NONE |
GPO 2 | Profile A lamp | 2 | Active when Profile A |
GPO 3 | Profile B lamp | 3 | Active when Profile B |
GPO 4 | Profile C lamp | 4 | Active when Profile C |
GPO 5 | Profile D lamp | 5 | Active when Profile D |
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