Sample Configuration For High Resolution Frequency Mode - Allen-Bradley 1756-CFM User Manual

Chapter 5 Configure the Configurable Flowmeter Module
Sample Configuration for
High Resolution
Frequency Mode
88
High Resolution Frequency mode provides speed control of machinery such as
turbines where shutdown on acceleration or speed is required independent of
the owner-controller. Speed is calculated without the K-factor but includes the
meter factor and CCF for special calculations.
When using this mode, you can calculate resolution by using this equation to
calculate resolution.
-9
F (250 x 10
in
Resolution =
T
sample
Table 6 - Sample Resolutions
F
in
60Hz
5000Hz
50,000Hz
The values listed in Table 6
change according to your application.
This section offers a sample configuration to configure your module for High
Resolution Frequency mode. In this configuration, channel 0 is configured
and channel 1 is left unused.For a detailed explanation of the features available
in this mode, see page
Follow the steps below to configure your module for High Resolution
Frequency mode.
1. Create a new module, see
2. Set all communications options, including:
• name
• communication format
• slot number
• minor revision
• electronic keying
• RPI - For this application, the minimum RPI = 5 ms
See pages 73 to 76.
Rockwell Automation Publication 1756-UM010C-EN-P - June 2021
Where:
)
• F is the input frequency
in
• T is the sample time period
sample
T
sample
0.033 seconds
0.020 seconds
0.050 seconds
are listed for example purposes. Specific values will
31.
page 72.
Resolution
0.00045Hz
0.0625Hz
0.25Hz