Triggered Recording

The proportion of pre-trigger data may be less than specified if the trigger event occurred before enough packets were recorded in the circular buffer (particularly after clearing the buffer).

For example, if the available memory will hold a 20 second recording, with 25% pre-trigger specified and an event-triggered recording starting five seconds or more into the run, the contents of the recorded file will be:

Trigger

Run

 

 

 

 

File

25%

 

75%

 

0

10

time in seconds

20

30

If the Trigger event was detected earlier than five seconds into the run, the

20 second file will contain all of the data up to the Trigger. If recording was triggered at three seconds only the first 15% of the file would hold pre-trigger data. The file contents would be:

Trigger

Run

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

File

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15%

 

 

 

 

 

85%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

10

 

time in seconds

20

 

 

 

30

Triggered Recording Operation

The Operation section of the Triggered Recordings dialog is used to arm the trigger before recording and shows the status of the recording activity.

MTM400 MPEG Transport Stream Monitor User Manual

3-103