Omron Sysmac NX Series User Manual page 260

Appendices
Functions To Use
The following functions are used in the design examples.
• High-speed Analog Inspection Library of Sysmac Library
DeviceVariableToArray_100 (Join Device Output Data)
DataRecorder (Data Recorder)
LogDataToCSV (Write Log Data to CSV File)
• Moving average filter of digital filtering
In this example, the moving average filter is used to attenuate the signals in the specific frequency
because the effect of periodic noise is assumed.
Refer to Moving Average Filter on page 8 - 23 for information on the moving average filter.
Additional Information
Use the digital low-pass filter to stabilize analog input values if measurement values are unsta-
ble due to the effects of non-periodic noise. In digital low-pass filtering, the smaller the cutoff
frequency is, the wider range of noise you can remove. This stabilizes the analog input values,
but causes the step response time to increase. Set the value of the cutoff frequency after you
consider the requirements of the response time. Refer to Digital Low-pass Filter on page 8 - 20
for information on the digital low-pass filter.
Digital Filter Setting Procedure
The following gives an example procedure for designing digital filters.
1
Execute the program that uses the High-speed Analog Inspection Library of Sysmac Library
and export the log data to a CSV file.
Refer to A-4-3 Programming Example on page A - 25 for a programming example.
2
Open the exported CSV file in Microsoft Excel, and then create a broken line graph with the
axis specifications below.
Item
Vertical axis
Horizontal axis Number of data items
Adjust the display range of the vertical axis and horizontal axis so that you can analyze the
fluctuation frequency of the Ch1 Analog Input Value.
The following gives the CSV file format and data layout.
A - 22
Specification
Ch1 Analog Input Value
NX-series Analog I/O Units User's Manual for High-speed Analog Input Units (W592)