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Rockwell Automation Publication 1440-UM001D-EN-P - September 2016 155
CIP Objects Appendix B
Tachometer Channel
Object (Class ID 326
H
)
The Tachometer Channel Object models front end processing that is
performed on a tachometer signal before specific measurements are performed.
Class Attributes
The Tachometer Channel Object provides no class attributes.
Instance Attributes
Services
Table 85 - Tachometer Channel Object Instance Attributes
Attribute ID Access Rule Name Data Type Description Semantics
3 Get/Set Number of Pulses per
Revolution UINT The number of signal pulses per
revolution of the shaft (for example
number of gear teeth).
0 = Tachometer disabled
> 0 = Tachometer enabled
4 Get/Set Auto Trigger BOOL Indicates whether the trigger level is
determined automatically from the
signal. 0 = Use specified Trigger Level, Trigger Slope,
and Hysteresis
1 = Automatically determine trigger level and
trigger slope, and use the specified Hysteresis
5 Get/Set Trigger Level REAL The signal level to be used as the
trigger.
Volts
6 Get/Set Trigger Slope USINT The slope of the signal at the threshold
crossing to be used as the trigger.
0 = Positive
1 = Negative
7 Get/Set Trigger Hysteresis REAL The amount of hysteresis around the
trigger level.
In Auto Trigger mode, this value is a percentage
of the peak-to-peak input signal and can range
from 0…50%. In Manual Trigger mode, this
value is a voltage level (the hysteresis voltage is
added or subtracted to the threshold voltage to
determine the hysteresis range).
8 Get/Set Name STRING2 A name to help identify this channel. 18 characters maximum
10 Get/Set Fault Time-out USINT Number of seconds with no pulses
before a Tach Fault is indicated unless
Zero Pulse Fault Inhibit is set to 1. 1…64 seconds
11 Get/Set Zero Pulse Fault Inhibit BOOL Lack of Tach Pulses does not cause a
Tach Fault.
0 = A lack of tach pulses constitutes a Tach Fault
1 = A lack of tach pulses does not constitute a
Tach Fault
Table 86 - Tachometer Channel Object Services
Service Code Class/Instance Usage Name Description
0E
h
Instance Get_Attribute_Single Returns one attribute.
10
h
Instance Set_Attribute_Single Sets one attribute.
(1)
(1) Attributes can only be set while the device is in Program mode. See the description of the Device Mode Object for more
information.