Data recorder burst data
The Data Recorder module’s Pre-trigger Records setup register specifies how many pre-event records are saved with each triggered recording. The Post-trigger Records setup register specifies how many post-event records are saved with each triggered recording.
Both Pre-trigger Records and Post-trigger Records are set to zero by default. To configure the data recorder for burst data logging, either or both of these setup registers must be set to a non-zero positive integer value.
The data log set for each triggered recording is equal to the sum of Pre-trigger Records + Post-trigger Records + 1 (where 1 is the actual record when the Data Recorder module’s Record input was triggered).
For example, if Pre-trigger Records is set to 10 and Post-trigger Records is set to 5, the number of records for each data log set is 16:
Burst data log set = [pre-trigger records] + [post-trigger records] + [actual trigger record] = 10 + 5 + 1 = 16.
When burst data logging is enabled, both Buffer Depth and Depth setup registers must be set to a positive integer multiple of the data log set.
Use the system frequency to calculate the number of records needed to capture 1 second of data:
For 60 Hz, total number of records per second = 60 cycles/second x 2 half-cycles = 120
For 50 Hz, total number of records per second = 50 cycles/second x 2 half-cycles = 100
You can use the Power Quality setup assistant in ION Setup to specify how many seconds of pre-trigger and post-trigger data you want to capture. ION Setup automatically calculates the required number of records based on your input.