If there is no force being recorded by the unit, make sure the inhibit switch on the controller is in the run position.
- If it is set to stop it will not record anything, and the baseline force profile will look like a 60Hz square wave when viewed in software
- If it is in run, then check to see if the force offset dial is at 10. If the unit is at 0 then it is likely there will be no force recorded without a force control command in the software.
If neither of these apply, check to see if there is a voltage change on the force display of the controller when you press on the lever arm/footplate. If not, ensure the black and grey motor cable is connected properly as per above. If that’s not the case then it is possible the motor is broken. To check this, substitute a second motor of the same type (if possible) and if the problem is not resolved then the motor is likely broken.
You can also check the motor fuse which is located inside the controller. The fuse cartridge can be removed from the holder and tested for continuity with a voltmeter.
Should the voltage change on the controller but not on the software (blank force/length displays, a flat line on the live data monitor or empty data files) then the dual-mode lever is likely working but there may be some issue with the connection to the software or with the software itself.
No force or length traces generally means that the software is not communicating properly with the DAQ or the instrument itself. In order to troubleshoot this:
- open File → live data monitor
- tap the dual-mode lever arm or footplate to see if there is any change in force
- if you observe a change in force on the live data monitor, then the lack of force on your trace is likely resulting from no stimulation, or your muscle is not viable. (please go to the end of the page for more information on how to troubleshoot an issue like this)
- If there is no force change on the live data monitor and the channel displays in the main window of DMC are blank, (see Figure 3) ensure that the proper instrument and channel setup has been done. Open Setup → My Instruments to confirm you have added the correct instrument. If so, open Setup → channel setup and confirm that the instrument you’re using has been set as your Length In/Out and Force In/Out device (in the case of a Dual-Mode)
The 300C Dual-Mode Muscle Lever communicates with DMC via the signal interface and some form of A/D card or integrated USB box so if there is no force change from the above steps you should inspect these closer:
- check that the BNC connections are made correctly between the 300C Dual-Mode Muscle Lever and the 604A or associated interface.
- ensure the ribbon cable or USB cable connecting the interface to the PC or laptop is connected properly
- If you have a PCI card, check to see if this is seated properly in the slot, or move it to another slot if available.
If the connections have been made correctly, and the issue still persists, please follow the instructions:
- locate and open the NI Max program on your PC
- click on devices and interfaces on the main screen (the model of the DAQ you are using should be listed here, there should be an icon that is green showing it is working)
If there are multiple devices on there (i.e., Dev 1, Dev 2) and only one is working then it is likely that there was a second device accidentally installed by Windows and DMC is communicating with the wrong one.
- go to DMC → File → Open Log Folder and delete the file DAQdevice.ddv
- reopen DMC, select the device that is working (i.e. Dev 2), then ‘remember my selection’ and OK.
- check to see if the communication is now restored via live data monitor.
This can more commonly occur when frequently connecting and disconnecting a USB DAQ device or after a Windows update.
If there is a single device present and it is not communicating properly then double check the PCI card and reseat it in the slot. Following the above step may result in a second device being created. In the off chance that it does, follow the steps above.
Figure 3. No communication between software and the lever system