Burst history
The Burst history DataMode™ is used to store data for transient events in an efficient manner. It can capture data before and after user-defined triggering events occur. It is particularly useful in minimizing data storage consumption when channels are defined with high data sampling rates. All channels must have the same sample rate.
NOTE
When a large number of channels are selected for a DataMode, the GUI responsiveness can become sluggish. Typically with 500 channels or less, this is not overly intrusive to usability. However, if more than 500 channels are required for any given DataMode, it is recommended that users consider splitting the channels across multiple DataModes when possible; otherwise, users will need to be patient in regard to the GUI response when assigning or editing any of the DataMode parameters.
Generic parameters
Navigate in a dialog using a mouse pointer, keyboard Tab, up-arrow or down-arrow key (not a 10-key pad up- and down-arrow key). Mouse point or Tab between insertion points or options. Use the mouse or up-arrow or down-arrow keys to scroll among options. Click the mouse, Tab or Enter to select an option.
- Name: Each DataMode must have a unique name and contain only valid characters (invalid characters are single and double quotes, '\', '@', '#', '&', '<' and '>'). Invalid channel names are 'true' and 'false' (case sensitive).
- Description: Optional detailed description of the DataMode.
- Trigger mode: Select one of the following triggering options.
- When true: Storage of a burst record will be triggered whenever the trigger channel is TRUE.
- On false – true edge: Storage of a burst record will be triggered when the trigger channel transitions from FALSE to TRUE.
- Trigger channel: Select the desired logical input channel for burst triggering. The trigger channel must have the same sample rate as the input channels.
Trigger time
- Pre (secs): Specify the time period in seconds of data storage before the trigger.
- Post (secs): Specify the time period in seconds of data storage after the trigger.
- Storage mode: Select the preferred storage mode.
- Standard mode: This mode is provided for compatibility with the traditional SoMat DataMode implementations. In this mode, all burst records are the same size. However, no checks are made for triggers while a burst record is being stored. This can result in little or no post trigger data storage after significant events.
- Enhanced mode: This mode checks for triggers all of the time. This mode ensures that data is stored for the full post trigger period irrespective of when the trigger occurs. In short, it fixes a potential significant shortcoming of the Standard mode and for this reason it is the default and recommended mode. This can result in burst records being different sizes, which is not a significant issue.
- Number of bursts: Select the Unlimited option to store all triggered burst event records. Optionally, specify a limit on the number of burst records to be stored. Note that when the Enhanced storage mode is used, burst storage is terminated after the total burst data samples stored exceeds the size of the specified number of burst records times the Standard burst record size.
NOTE
The total number of samples stored in a Standard burst record is the sum of the post-trigger and pre-trigger samples plus one, since the trigger sample is always stored.
- Channel select: From the channels list, select the desired input channels for the DataMode and click the appropriate arrow. Alternatively, drag and drop the desired channels to the appropriate list. All channels selected must have the same sample rate.