A very common use of Logic Flows in Pathfinder Core PRO is to perform critical actions when an audio source or destination falls silent. For example, you could have a Logic Flow send you an email if the feed to the transmitter becomes silent. In order to accomplish this, you should use the Audio Alarms section of Pathfinder Core PRO.
Almost any audio source or destination in an Axia network can be monitored for silence, clipping, and audio presence.
Click the Routing and Audio > Audio Alarms link in the Navigation Bar to create, edit, and view audio alarms in the system.
Like other Pathfinder Core PRO pages, the Audio Alarms page updates dynamically as the alarm states change. Eleven columns are displayed for each audio alarm.
Column | Description |
|---|---|
Name | The name of the alarm. |
Type | The type of clearing alarm. Types can either be Silence or Clipping. If you wish to know when audio returns, use a silence alarm and then select the correct value for the Alarm state in Logic Flows. This will be discussed in greater detail below. |
Host | This displays the IP address and LWRP port of the device where the source or destination being monitored exists. |
SRC/DST | Displays whether the IO being monitored is a source or destination. |
Io | Displays the port number on the device of the input or output being monitored. |
Chs | The channels monitored: Any, All, Left or Right. |
Alarm Time | Displays the amount of time in milliseconds the selected source or destination must be silent (or clipping if the type is clipping) before the alarm is triggered. |
Release Time | Displays the amount of time in milliseconds that the selected source or destination must be not silent (or not clipping if the type is clipping) before the alarm is released. |
Timer State | This column shows the current countdown to Alarm Time or Release Time. For example, when a source being monitored goes silent, this column will show CountingToAlarm. Idle means that the source or destination is currently in the state represented by the AlarmState column. |
Enabled | This column shows if the alarm is enabled or is in a disabled fixed state of AudioPresent, Silent, or Clipping. |
Alarm State | This column represents the current state of the alarm. Possible values include Silent, AudioPresent, and Clipping. This value will only change after the source or destination maintains the requested state for at least the amount of time defined in the Alarm Time or Release Time properties. |
Silence and Clipping Thresholds
The settings above the list apply to every alarm:
Silence Threshold is the level, in dBFS, below which audio counts as silent (by default -80).
Clipping Threshold is the level, in dBFS, above which audio counts as clipping (by default -1).
Display Dynamic: set to True to also list the alarms that Pathfinder creates on its own, for example for meters and indicators in user panels. They are hidden by default.
To give a particular source or destination its own thresholds, click Advanced. The Advanced Audio Router Settings dialog lists every IO that has an alarm, with its Low Level and Clip Level:
A shaded value matches the default above and follows any change to it. Type a different value to give that IO custom thresholds, and click Apply. Two alarms on the same IO always share its thresholds. If you later change a default to the same value as a custom setting, that IO follows the default again.
Creating New Audio Alarms
Let’s create an example.
Click the Routing and Audio > Audio Alarms link in the Navigation Bar to create, edit, and view audio alarms in the system. On the Audio Alarms page, click Add + to add an Audio Alarm.
Complete the fields on the Audio Alarm Editor.
Field | Notes |
|---|---|
Audio Alarm Name | Type a name for this Alarm. In the example above, AirChain. |
Alarm Type | Select the alarm type from the drop-down list. Options include Silence and Clipping. |
Alarm Time (ms) | Alarm time is the number of milliseconds the audio must be in the specified state before the alarm becomes active. The example above defines an alarm time of 15000ms or 15-seconds. |
Alarm Release Time (ms) | Alarm release time is the amount of time the audio needs to be in the opposing state after an alarm has tripped before the alarm clears. The example above defines an alarm release time of 5000ms, or 5-seconds. |
Alarm Channels | From the drop-down list, specify the channel the system should monitor to determine the alarm state. Options include Any, All, Left, or Right. |
Source/Destination | Select whether the alarm will be on a Source or Destination. |
Enabled | From the drop-down list, select the desired fixed state while disabled or leave at Enabled. |
IO | Click the ellipsis button to choose from the list of available sources or destinations. |
After clicking on the ellipsis button to open the Select IO screen (either Select Source or Select Destination, depending on how this alarm is configured), select the source or destination from the IO list and click Select.
Click Apply to save your changes to this alarm.
Monitoring Alarms from the Audio Alarms List
The Audio Alarms list view, like most lists in Pathfinder Core PRO, shows alarm status changes in real time.
For example, the Timer State and Alarm State values will dynamically update in this list as alarm states change. This can be an excellent troubleshooting tool.
Using Alarms in Logic Flows
Once an alarm has been created, it is available for use in Logic Flows. In the Logic Flow below, we have created a Logic Flow that turns on a warning lamp on GPO port 2 pin 5 whenever the AirChain audio alarm has its Alarm State switch to Silent:
If we wanted to perform a different action when the alarm releases (audio returns), we would use the AudioPresent value in the translation list. For example, the following Logic Flow will write Air chain OK to the AirChainStatus memory slot when audio is present and AIR CHAIN SILENT when there is silence.
More possible audio alarm Logic Flows examples are covered in the Email Messages section since that is a common action to be taken when things get quiet.