Rockwell Automation 1756-CFM ControlLogix Configurable Flowmeter Module User Manual
Page 56
56
Rockwell Automation Publication 1756-UM010B-EN-P - December 2011
56 Configurable Flowmeter Module Features and Operational Modes
If the input frequency is greater than 100Hz-200Hz, the K-factor is
interpolated as follows:
If the input frequency is greater than 200Hz-300Hz, the K-factor is
interpolated as follows:
If the input frequency is greater than 300Hz, the K-factor used
is always 100.0. There is no K-factor calculation over 100Hz.
To use Gross Rate, you must set the K-factor values in Module Tags, as shown
below.
K-factor = (f
in
- 100.0) x
(71.0 - 25.0)
(200.0 - 100.0)
x 25.0
K-factor = (f
in
- 200.0) x
(111.0 - 71.0)
(300.0 - 200.0)
x 71.0
Name
Style
Data type
Value
Change during
operation
C.Operations[0].kFactStruct.kFactorForChan[0]
Float
REAL
25.0
1
Yes
C.Operations[0].kFactStruct.kFactorForChan[1]
Float
REAL
25.0
1
Yes
C.Operations[0].kFactStruct.kFactorForChan[2]
Float
REAL
71.0
Yes
C.Operations[0].kFactStruct.kFactorForChan[3]
Float
REAL
111.0
Yes
C.Operations[0].kFactStruct.kFactorForChan[4]-
C.Operations[0].kFactStruct.kFactorForChan[12]
Float
REAL
0
Yes
C.Operations[0].kFactStruct.FreqAtKFactor[0]
Float
REAL
0.0
Yes
C.Operations[0].kFactStruct.FreqAtKFactor[1]
Float
REAL
100.0
Yes
C.Operations[0].kFactStruct.FreqAtKFactor[2]
Float
REAL
200.0
Yes
C.Operations[0].kFactStruct.FreqAtKFactor[3]
Float
REAL
300.0
Yes
C.Operations[0].kFactStruct.FreqAtKFactor[4]-
C.Operations[0].kFactStruct.FreqAtKFactor[12]
Float
REAL
0
Yes
1
To avoid discontinuity when interpolating Gross Rate, make sure the values in C.Operations[0].kFactStruct.kFactorForChan[0] and C.Operations[0].kFactStruct.kFactorForChan[1] match.
IMPORTANT
For more information on setting values in the Module
Tags, see