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APPENDIX B
53
of the first data sample in each retrieved data record. The time of trigger event is returned in the
AdditionalData
parameter.
Timestamp Source
Timestamp value
Resolution
System (IEEE 1588)
PTP or TAI (International Atomic Time)
20 ns
PXIe_CLK100
Elapsed time from last SYNC
20 ns
PXI_CLK10
Elapsed time from last SYNC
100 ns
Table 4-3: Timestamp Source and Resolution
A
DDITIONAL
D
ATA
The additional information associated with the data records are returned as a JSON (Java Script
Object Notation) array of name/value pairs:
[[JSON array for channel 1
’s first record
], [JSON array for channel
2
’s first record], ….]
The JSON object array for each channel is:
[{Object1}, {Object2}
, …]
Each object is a list of name/value pairs:
{name1:value1, name2: value2
,…}
JSON objects can be parsed using the following defined name strings.
Object
Name String
Value
Over range
Over-Range
True when any overload status bit is set.
Trigger time
Trigger Timestamp
Seconds
The trigger timestamp in seconds
Trigger Timestamp
Fraction
The fraction portion of trigger timestamp.
Dropped trigger
timestamp_sec
The timestamp of when the trigger would have
occurred.
timestamp_frac
The fraction portion.
Trigger Dropped
The channel name of the lost trigger.
Table 4-4: Additional Data JSON Names and Values
