Setting up National Instrument Multifunction Data Acquisition devices (NI DAQ) to capture energy data
As an alternative to the Energy Probe, you can use a NI DAQ device to gather energy data from your target and view the results in Streamline.
To collect power statistics using a NI DAQ device, you must have the following:
- NI DAQ hardware.
- NI-DAQmx software installed on your host machine. This software package includes drivers for the NI DAQ device. You must use the NI-DAQmx Base software on Linux.
In addition, you must set the location of the appropriate caiman application using the Tool Path field in the Capture & Analysis Options dialog box. If the pre-built caiman executable that is distributed with Streamline is insufficient, or you want to change some options, you can re-build caiman from source. For example, to build a NI DAQ enabled version of caiman for Red Hat Enterprise Linux 6, you first need to set the following values in CMakeLists.txt:
SUPPORT_UDEV 0
.SUPPORT_DAQ 1
.NI_RUNTIME_LINK 0
.
Also, verify the NI DAQ install paths within CMakeLists.txt.
See README.md located in DS-5_install_directory
/sw/streamline/energy_meter/caiman/ for
more details about setting up NI DAQ and running caiman.
See the National Instruments website, http://www.ni.com for the list of operating systems supported by NI DAQ.
To set up your NI DAQ device, follow these steps:
Procedure
- Connect the Ai1 connections on the NI DAQ device to go across the shunt resistor on your target.
- Connect Ai0 negative to ground.
- Also connect Ai GND to ground.
-
Loop Ai0 positive to Ai1 negative.
The Ai0 connectors are measured across the load, which is used to derive the voltage.
Figure 10-6 Connections for NI USB-621x
- Repeat steps 1 through 3 using the other connectors on the NI DAQ device to measure additional channels.
- In the Streamline Data view, click Capture & Analysis Options.
- Select the NI DAQ option from the Energy Capture drop-down menu.
-
Enter a valid system name in the Device field.
To get the system name of your National Instruments device, you must run the NI-DAQmx Base List Devices application, installed as part of the NI-DAQmx software package.
- Click the Select the energy capture tool button in the Tool Path field.
- Locate either the pre-built caiman in your DS-5 installation directory, or the modified version that you built from source, and select it.
- Click Open.