Rockwell Automation 1440-DYN02-01RJ XM Dynamic Measurement Module - Manuel (Page 144)

144 Publication ICM-UM002F-EN-E - March 2013
Appendix B CIP Objects
Speed Measurement Object
(Class ID 325
H
)
The Speed Measurement Object models a speed measurement of a tachometer
signal.
Class Attributes
The Speed Measurement Object provides no class attributes.
Instance Attributes
Table B.44 Speed Measurement Object Instance Attributes
Attr ID
Access
Rule Name Data Type Description Semantics
3 Get Speed Value REAL The measured speed
value. CPM
4 Get Status BOOL Indicates if a fault or
alarm has occurred. 0 = Operating without alarms or
faults.
1 = Alarm or fault condition
exists. The
Speed Value
attribute may not represent the
actual field value.
5 Get Maximum
Speed REAL The maximum (peak)
measured speed value
since the most recent
reset. CPM
12 Get Time Constant UINT The time constant value
used for exponential
averaging of the
Speed
Value (a low pass
filter/output smoothing
filter).
Milliseconds
You can set this using the
TachResponseTime
configuration tag in the RSLogix
5000 software.
Refer to I/O
Data Tags on page 91 .
13 Get Acceleration REAL The rate of change of the
Speed Value.
CPM/min
14 Get/Set Measurement
Response USINT Determines how quickly
the Speed measurement
responds to change. For
example, setting this
attribute to 1 indicates a
settling time of 220 ms.
This means that the speed
is averaged over a quarter
second, and the reported
value will reach 90% of
the new steady state
value about 220 ms after
the change in machine
speed. See table below.
Meas.
Response
Settling
Time
Time
Constant
0 2640 ms 1200 ms
1 220 ms 100 ms
2 22 ms 10 ms