Allen-Bradley 1444-TSCX02-02RB User Manual page 394

Appendix A CIP Objects
394
See Reading FFT Data on page 333
from the read data.
Waveform (eTWF, eTWF_ALARM)
Table 122 - Record Type Structures
Byte Offset Structure Member Data
Within
Structure
0 TimestampNanoSec
4 TimestampSec
8 SamplePeriodInSecs
12 Identifier
16 RelativeTime
20 ByteCount
24 SampleArray
See Reading TWF Data on page 332
from the read data.
Tacho (eTACHO, eTACHO_ALARM)
Table 123 - Record Type Structures
Byte Offset Structure Member
Within
Structure
0 TimestampNanoSec
4 TimestampSec
8 Reserved
12 Reserved
16 Reserved
20 ByteCount
24 TimingArray
For FFT and TWF data
For asynchronous data, the actual sample period is transferred (REAL format).
For synchronous data, the same four bytes are used to transfer the number of
samples per revolution and an indicative speed for the transferred data.
Rockwell Automation Publication 1444-UM001D-EN-P - June 2018
for details on how to calculate the FFT
Description
Type
UDINT Subsecond accuracy.
UDINT Seconds since 1970.
REAL Time period between samples.
DWORD Data source, mode, tacho source, and measurement units.
UDINT A 24-bit (micro-second) counter-value for finely aligning data.
See Reading Continuous Time Waveforms on page 329
information on using this parameter.
UDINT The size of the following array in bytes.
REAL The array of waveform data values (samples).
for details on how to calculate the TWF
Data Description
Type
UDINT Subsecond accuracy.
UDINT Seconds since 1970.
REAL
DWORD
UDINT
UDINT The size of the following array in bytes.
UDINT The array of tacho time values (24 bit, micro-second counter).
for