Allen-Bradley 1444-TSCX02-02RB User Manual page 404

Appendix A CIP Objects
404
The Record Type Structures are as follows.
Table 131 - Discrete Data
Byte Offset Structure Member
Within
Structure
0 TimestampNanoSec
4 TimestampSec
8 Reserved
12 Reserved
16 Params0
20 Params1
24 Params2
28 Params3
32 ByteCount
36 DataArray
Table 132 - FFT (eFFT_TDx)
Byte Offset Structure Member
Within
Structure
0 TimestampNanoSec
4 TimestampSec
8 SamplePeriodInSecs
12 Identifier
16 ucDataSelect
17 ucSpeedByte0
18 ucSpeedByte1
19 ucSpeedByte2
20 ByteCount
24 LineArray
See Reading FFT Data on page 333
from the read data.
Rockwell Automation Publication 1444-UM001D-EN-P - June 2018
Data Type Description
UDINT Subsecond accuracy.
UDINT Seconds since 1970.
DWORD
DWORD
DWORD Set bits indicate which parameters are included in the
data array. The values in DataArray are in the order of
DWORD
the set bits. Values are the same as configuration tag
TransientCapture.DiscreteParams1...4.
DWORD
DWORD
UDINT The size of the following array in bytes.
REAL The array of data.
Data Description
Type
UDINT Subsecond accuracy.
UDINT Seconds since 1970.
REAL Time period between samples or speed and no of samples per
revolution.
DWORD Data source, mode, tacho source, and measurement units.
BYTE Not used for transient data. Only Magnitude data is available.
Bit 3 is set if FFT Data Filter has been applied.
BYTE RPM value of the referenced speed source for the FFT data.
Actual RPM = Value/100
Value that is provided is a 24 bit (3 byte) integer.
First (least significant) byte, bits 0...7
BYTE Second byte, bits 8...15
BYTE Last byte, bits 16...23
UDINT The size of the following array in bytes.
REAL The array of FFT line amplitude data.
for details on how to calculate the FFT