Hawk GUI: Trigger Configuration

The Trigger Automation page allows users to configure ‘triggers’. Triggers are system responses to events that occur during data acquisition. They can be used to automatically put the system into (or out of) a writing state, or to take a manoeuvre.

The trigger setup screen can be accessed from the general configuration page, or the acquisition screen.

Add/Remove a Trigger

  1. Select the category: trigger to start / stop writing, or start / stop a manoeuvre.
  2. Add a trigger by clicking on the + button
  3. Edit the trigger description
  4. Edit the trigger settings
  5. Delete the trigger in the targeted row

Then define the trigger:

  1. Tigger type: those are described in the following sections
  2. Arm Condition: Optional, this condition must be met in before the trigger begins evaluating the start condition.
  3. Start Condition: when this condition is met, the trigger will execute (start write or start manoeuvre depending on the trigger category).
  4. Stop Condition: Optional, when this condition is met the trigger operation will cease (stop write or stop manoeuvre depending on the trigger category).
  5. Trigger repeats: if set, this defines the number of times the operation should be executed if the start condition is met multiple times (and arm condition where relevant). If not set, there is not limit.
  6. Minimum runtime: if set, this defines the minimum period of time for which the trigger will be active. Where a stop condition is defined, the minimum runtime takes precedence; the operation of the trigger will stop only when stop condition is met and the minimum runtime has expired.
  7. Maximum runtime: If set, this defines the maximum period of time for which the trigger will be active. The operation of the trigger will cease once the trigger has been active for the maximum runtime (unless it has already stopped because the stop condition has already been met).
  8. Abortable period: if set, the start condition has to remain true for the duration specified, otherwise trigger will cease.
  9. Manoeuvre Type: This field defines the type of the manoeuvre (manoeuvre types are defined in the preferences page). This field is only available if the trigger category is ‘manoeuvre’.
  10. Pre-Offset: Pre-Offset modifies the start time of the automatically captured manoeuvres by a fixed amount of time. This means that the start condition of the trigger does not necessarily need to define the exact start time of the manoeuvre. This field is only available if the trigger category is ‘manoeuvre’.
  11. Post-Offset: Post-Offset modifies the end time of the automatically captured manoeuvres by a fixed amount of time. This means that the stop condition of the trigger does not necessarily need to define the exact stop time of the manoeuvre. This field is only available if the trigger category is ‘manoeuvre’.
  12. Validate the changes
  13. Cancel the changes

The 3 conditions (Arm / Start / Stop) can be based on a gradient (rate of change) of the quantity we are monitoring, or an absolute value of this quantity. The quantity we are looking at depends on the type of trigger.

Speed based trigger

Speed trigger looks at the speed value of a given channel of type “SHAFT”. In the arm, start, and stop conditions, speed value can be expressed in RPM / percentage of the maximum speed, or Hz.

Alarm based trigger

Alarm based trigger looks at the alarm status of a particular channel. That takes into account any broadband, mode, or phase alarm defined for this channel (see chapter 7 – Alarm monitoring).

There are no arm / start / stop conditions to define here. The start condition is: “channel goes into alarm”. The stop condition is: “channel comes out of alarm”.

DC trigger

DC trigger looks at the DC level of a particular channel. This is useful for steady state or transient data, with slowly varying values.

 Amplitude trigger

Amplitude trigger looks at the peak value of a particular channel. The peak value can be expressed as peak, peak-peak or RMS. This is useful for dynamic data where the overall envelope level is of interest, e.g. noise or vibration.

Time based trigger

Start / stop conditions are based on acquisition data time. User can specify a start time and optionally a stop time. Or use maximum run time and repeat period to write / take manoeuvres at regular intervals. In the example below, we will start a first manoeuvre at 1pm (start condition), and then will take 30 seconds long manoeuvres (maximum run time) every minute (repeat period).

Monitoring trigger state while running

Users can see the state of the various triggers that have been setup, during acquisition as shown below:

No trigger has been setup

No trigger is active

One active trigger