SCXI Cascading: SCXI-1125 to SCXI-1141/1142/1143 Modules
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Cascading SCXI modules gives you greater flexibility to condition analog signals, but improper programming of cascaded modules can actually lead to decreased accuracy in your measurements. Therefore, only use cascading if you are qualified in this advanced method of signal conditioning.
Cascading allows you to combine the functionality of multiple SCXI modules to perform one data acquisition process. This example program demonstrates the use of two SCXI modules in a cascaded system. The first stage is an SCXI-1125, which provides high-voltage isolation and signal amplification. The output signals from the SCXI-1125 are passed to the SCXI-1141, SCXI-1142, or SCXI-1143, which filters the incoming signals using an 8th order programmable lowpass filter. The exact frequency response of the filter depends on which SCXI module you are using. The SCXI-1141 has an Elliptical filter, the SCXI-1142 has a Bessel filter, and the SCXI-1143 has a Butterworth filter. Refer to the SCXI-1141/1142/1143 User Manual for more details on the frequency, step, and phase response of each module.
Because cascading programatically adjustable SCXI modules such as the SCXI-1125 and SCXI-1141/1142/1143 is an advanced application, NI strongly recommends using a combination of hardware and digital (or software) filtering to achieve equivalent results as cascading an isolation module with a hardware filter (such as the SCXI-1120) with a filtering module. An anti-aliasing filter is necessary and can be provided by the SCXI-1125. Digital filtering can provide equivalent results for noise and error reduction with greater flexibility than hardware filters. Review Chapter 4 of the LabVIEW Analysis Concepts Manual in related links below for more information.
While cascading SCXI modules provides additional opportunities for creating complete signal conditioning solutions, you should excercise great care when configuring and calibrating a cascaded SCXI system. Improper programming of cascaded modules can actually lead to decreased accuracy in your measurements.
Instructions for use are attached below.
Filename: 202233.txt
Application Software: LabVIEW Full Development System 6.1
Language(s): LabVIEW
Hardware Group: Multifunction DAQ (MIO)
Driver: Traditional NI-DAQ (Legacy) 6.9.3
Filename: 1125_114x.llb
Application Software: LabVIEW Full Development System 6.0
Language(s): LabVIEW
Hardware Group: Multifunction DAQ (MIO)
Driver: Traditional NI-DAQ (Legacy) 6.9.1
Cascading allows you to combine the functionality of multiple SCXI modules to perform one data acquisition process. This example program demonstrates the use of two SCXI modules in a cascaded system. The first stage is an SCXI-1125, which provides high-voltage isolation and signal amplification. The output signals from the SCXI-1125 are passed to the SCXI-1141, SCXI-1142, or SCXI-1143, which filters the incoming signals using an 8th order programmable lowpass filter. The exact frequency response of the filter depends on which SCXI module you are using. The SCXI-1141 has an Elliptical filter, the SCXI-1142 has a Bessel filter, and the SCXI-1143 has a Butterworth filter. Refer to the SCXI-1141/1142/1143 User Manual for more details on the frequency, step, and phase response of each module.
Because cascading programatically adjustable SCXI modules such as the SCXI-1125 and SCXI-1141/1142/1143 is an advanced application, NI strongly recommends using a combination of hardware and digital (or software) filtering to achieve equivalent results as cascading an isolation module with a hardware filter (such as the SCXI-1120) with a filtering module. An anti-aliasing filter is necessary and can be provided by the SCXI-1125. Digital filtering can provide equivalent results for noise and error reduction with greater flexibility than hardware filters. Review Chapter 4 of the LabVIEW Analysis Concepts Manual in related links below for more information.
While cascading SCXI modules provides additional opportunities for creating complete signal conditioning solutions, you should excercise great care when configuring and calibrating a cascaded SCXI system. Improper programming of cascaded modules can actually lead to decreased accuracy in your measurements.
Instructions for use are attached below.
| Related Links: |
| LabVIEW Analysis Concepts |
| Getting Started with SCXI |
Requirements
Filename: 202233.txt
Software Requirements
Application Software: LabVIEW Full Development System 6.1
Language(s): LabVIEW
Hardware Requirements
Hardware Group: Multifunction DAQ (MIO)
Driver: Traditional NI-DAQ (Legacy) 6.9.3
Software Requirements
Application Software: LabVIEW Full Development System 6.0
Language(s): LabVIEW
Hardware Requirements
Hardware Group: Multifunction DAQ (MIO)
Driver: Traditional NI-DAQ (Legacy) 6.9.1
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