Frequently Asked Questions
If the EMG system specified in the Hardware Configuration has clipping and line interference outputs, these lights will illuminate in EMGworks when the signal is being clipped or there is line interference in the signal. If the EMG system specified in the Hardware Configuration does not have clipping and line interference outputs, these lights can be disabled by choosing Options from the Tools menu and un-checking the Display Clipping and Line errors check box in the Options dialog box. The control signals for the software indicators come from the Bagnoli 4/8/16 Main Amplifiers.
This situation commonly occurs if the result of the calculation is only 1 datum point. It is not possible for the EMGworks graph tools to plot only 1 datum point, since at least 2 points are required to draw a line. The single datum point can be easily viewed by using the “gridview” feature in the “view “menu. Note that versions of EMGworks 3.6 and higher will display the X and Y coordinates of the datum point on the plot area.
Data Acquisition File Structure
Data Acquisition TESTS consists of one or more SETS, each of which can be executed once, or repeated multiple times. The repetition of a SET is referred to as a “REP”.
- Files terminating in “*.emt” are the TEST files; these describe all the parameters associated with a TEST.
- Files terminating in “*.emg” are raw data files acquired during a single “REP” (i.e. repetition) of a SET.
The minimum number of files generated during data acquisition is one file for the TEST parameters (*.emt) and one file for the one repetition of a data SET (*.emg). Multiple repetitions of a SET result in multiple files terminating with *.emg.
Example: A TEST consisting of two SETs, each repeated twice results in the following files:
Data Analysis File Structure
All data analysis is performed within the context of a WORKSPACE. The WORKSPACE is a concept used to track all active data files and plots used during an Analysis session.
- Files terminating in “*.ewp” are WORKSPACE files.
- Files terminating in “*.emc” are data sets resulting from performing an EMGworks calculation. These files can be generated from raw data (*.emg files) or from other calculation outputs (*.emc files).
- Files terminating in “*.emp” are plot files. Their function is to graph either *.emg files or *.emc files.
Example: A simple workspace that contains an imported TEST, with a single calculation and a single plot would consist of the following files:
Note that the raw TEST data terminates with *.emt and *.emg files. These files are needed by the WORKSPACE, but are generated during Data Acquisition and may not necessarily reside in the same location as the WORKSPACE files.
Mathworks has acknowledged this as a bug in MATLAB 7.0 (R14) and MATLAB 7.0.1 (R14SP1). Their recommendation is presented below:
There are several known issues with the COM interface shipped with MATLAB 7.0 (R14) and MATLAB 7.0.1 (R14SP1). See the problem descriptions below for more information.Fixes for all of the problems listed below have been addressed in an updated version of comcli.dll. You should replace the current version in your MATLAB installation with this updated version. Here are the required steps:
- If you have not already done so, upgrade to MATLAB 7.0.1 (R14SP1). The revised version of comcli.dll will work only with this version of MATLAB.
- Quit MATLAB.
- Rename the following file: $MATLABbinwin32comcli.dll (where $MATLAB is the MATLAB root directory on your machine) to$MATLABbinwin32comcli.dll.old.
- Download the new file: comcli.dll and place it in the same directory mentioned in step 3.
- Restart MATLAB
- After restarting MATLAB, issue the following command at the MATLAB prompt: rehash toolboxcache.
Note that if you use MATLAB Compiler to deploy applications that use the COM Interface, you will have to package the revised comcli.dll separately. On the target machine, the revised comcli.dll should replace the original in $MCR_ROOTbinwin32.
Note that to use the “Export to MATLAB” feature, you need to run EMGworks with administrator privileges. An alternative approach is to run the “Load EMG” script within the MATLAB environment and import *.emg files directly.
There are three possible reasons for this:
- The network is already configured. In this situation, you already can establish connectivity and there is no need to configure the adapter again.
- The Wireless Zero Configuration service is stopped. (You may also see error 1059.) In this case, go to Control Panel, choose Administrative Tools, choose Services, right click Wireless Zero Configuration, and choose Start.
- Configuration is disabled on the wireless adapter. In this case, double click the adapter icon on the taskbar, click Change Advanced Settings, and navigate to the Wireless Networks tab. Make sure the item labeled “Use Windows to configure my wireless network settings” is checked.
You can test the board using the Test Panels in National Instruments Measurement and Automation (MAX).
- Open MAX. In the configuration tree, select your A/D card (under NI-DAQmx devices). Click the “Test Panels…” button.
- On the Analog Input tab, set the channel name to DevX/ai0, set the mode to On Demand, set the input configuration to RSE, and uncheck Auto-scale chart. Connect an EMG sensor to channel 1 on the amplifier and set the gain knob to 1k.
- Press Start. At this point you should see the data responding if you tap one of the silver bars with your finger. The signal should be flat when the bars are shorted.
To do this, you can expand the data set in the workspace tree so that you can see the channels within it. Hold down Ctrl and select the channels on which you would like to perform a RMS by clicking them, then right click and choose Calculations->RMS. In the RMS window, the Applies To section will list these channels.
To plot the processed channels in conjunction with the unprocessed channels, expand the RMS calculation as well. Then Ctrl-click to select the processed channels from one data set and the unprocessed channels from the original data set. You can then right click and choose Plot. (This operation can also be done within the Plot->Create Plot wizard.)
Use the Subset calculation to split your data into smaller data series. Right click on the file in the EMGworks Analysis tree and choose Calculations->Subset.
Given the subset of data within one window, the calculation will produce a single data point (for example, the RMS of the data in this window for a windowed RMS). This is repeated for each window within the data set. This reduction of data points means that the sampling frequency changes.
Select your data or calculation result in the workspace tree, then choose Tools->Export to CSV File. This will produce a comma-delimited text file which can be read by Excel and many other programs (including Notepad or other text editors).