Trigger time-out

Once the trigger conditions are set and the measurement is started, the instrument will wait until the trigger conditions are met before the post samples are measured and the measurement is finalized.

If the trigger conditions are set in such a way that the input signal(s) will never meet the trigger settings, the instrument will wait forever. When no measurement is performed, no signals will be displayed.

To avoid that the system will wait infinitely, a trigger time-out is added to the trigger system. When after a user defined amount of time after starting the measurement still no trigger has occurred, the trigger time-out will force a trigger. This will ensure a minimum number of measurements per second. On conventional desktop oscilloscopes, this is called Trigger mode AUTO and the used value is approximately 20 ms.

The trigger time-out is entered as a number, representing the delay in seconds. There are two special values for the trigger time-out setting:

  • trigger time-out = 0
    Immediately after starting a measurement a trigger is forced. Basically this bypasses the trigger system and the instrument always measures immediately. No pre samples are recorded. The instruments is free-running, just like when no trigger source is selected.
  • trigger-time-out = infinite
    The system will wait infinitely for a trigger. The software will never force a trigger, only when the trigger conditions are met, a trigger will occur and a measurement will take place. This setting is particularly useful for single shot measurements. On conventional desktop oscilloscopes, this is called Trigger mode NORM.

Changing the trigger time-out of a channel in the Multi Channel oscilloscope software can be done in various different ways:

  • Opening the trigger properties dialog and adjusting the trigger time-out.
  • Clicking the Trigger time-out infinite button on the instrument toolbar or pressing hotkey W will toggle the trigger time-out between the set value and infinite.
  • Clicking the Trigger Time-out 1 button on the instrument toolbar or pressing hotkey 1 will toggle the trigger time-out between the set value and infinite.
  • Clicking the Trigger Time-out 0 button on the instrument toolbar or pressing hotkey 0 will toggle the trigger time-out between the set value and zero.