« Close

Datasheets and User Guides

App Notes

Software & Driver


1.1 - Control Panel Application (LJControlPanel)

The LabJack Control Panel application (LJCP) handles configuration and testing of the U6. Click on the “Find Devices” button to search for connected devices.

Figure 1.1-1. LJControlPanel Device Window

Figure 1.1-1 shows the results from a typical search. The application found a U6 connected by USB. The USB connection has been selected in Figure 1-1, bringing up the main device window on the right side.

  • Refresh: Reload the window using values read from the device.
  • Write Values: Write the Local ID from the window to the device.
  • Config. IO Defaults: Opens the window shown in Figure 1-2.
  • Reset: Click to reset the selected device.
  • Test: Opens the window shown in Figure 1-3.
Figure 1.1-2. LJControlPanel U6 Configure Defaults Window

Figure 1.1-2 shows the configuration window for U6 defaults. These are the values that will be loaded by the U6 at power-up or reset. The factory defaults are shown above.

Figure 1.1-3 shows the U6 test window. This window continuously (once per second) writes to and reads from the selected LabJack.

Figure 1.1-3. LJControlPanel U6 Test Window

Selecting Options=>Settings from the main LJControlPanel menu brings up the window shown in Figure 1.1-4. This window allows some features to of the LJControlPanel application to be customized.

Figure 1.1-4. LJControlPanel Settings Window
  • Search for USB devices: If selected, LJControlPanel will include USB when searching for devices.
  • Search for Ethernet devices using UDP broadcast packet: Does not apply to the U6.
  • Search for Ethernet devices using specified IP addresses: Does not apply to the U6.



I have purchased LabJack U6 and CB37 terminal board.

I have connected AIN10 and AIN11 across a resistor and GND.

Now, I want to measure voltage drop across AIN10 and AIN11 (differential reading). Also, line voltage between AIN10 to GND (single ended reading).

I open up U6 test panel. I see readings against AIN10 and AIN11 also a checkbox against to enable diff against AIN10.

But I am not able to understand which reading is Single Ended and which is Differential as per my requirement.

Thanks in advance.

In the test panel in LJCP, AIN11 always displays single-ended.  AIN10 displays single-ended if "Diff" is not checked, and differential (AIN10-AIN11) if "Diff" is checked.

If you want to see AIN10 vs. GND, AIN11 vs. GND, and AIN10-AIN11 all at the same time, you can do that in LJLogUD.  Set 3 rows to 10-199, 11-199, and 10-11.

So are you saying you have some voltage or current source connected to AIN10, then a resistor from AIN10 to AIN11, then AIN11 jumpered to GND?  If AIN11 is jumpered to GND, then a differential reading AIN10-AIN11 is the same as a single-ended reading AIN10-GND.

Also, how big is your resistor?  If it is >1k, you might have to worry about settling errors.

I wanted to see AIN10 vs GND, AIN10-AIN11 at the same time. 

In the meantime, I used LJStreamUD as 10-199, 10-11 to get above.

My setup has AIN10 and AIN11 are connected to two points of sense resistors.

I want to check line voltage, so it can be checked by AIN10-GND and voltage drop on the resistor i.e. AIN10-AIN11.

Can we do this in LJCP?


No, in the test panel in LJCP you can only view AIN10-GND or AIN10-AIN11, not both at the same time.  Use LJLogUD as mentioned above to see all at the same time.  Or to use the test panel you can run a jumper from AIN10 to another channel and view that other channel single-ended.

Ok I am using LJStreamUD for getting AIN10-GND and AIN10-AIN11.

I have set up 2 channels as 10-199, 10-11.

Can I set different ranges for these 2 channels?

Also, what is difference between LJ_rgBIP1V and LJ_rgBIPP1V?

Manual says 3 ranges are supported +/-10, +/-1, +/-0.1, +/-0.01 at x1, x10, x100 and x1000 respectively.

Then dropdown box of ranges shows more ranges than 4.

What is significance of each one?


Yes you can set different ranges for different channels.  The dropdown lists all ranges for all devices, but the U6 only supports +/-10V (LJ_rgBIP10V), +/-1V (LJ_rgBIP1V), +/-0.1V (LJ_rgBIPP1V), and +/-0.01V (LJ_rgBIPP01V).  So, for example, the way you read LJ_rgBIPP01V is "BIPolar Point 01 Volts".  See Sections 2.6 & 4.3.3 of the U6 User's Guide.

If you pick other ranges, the UD driver will "round up" to the next available range, so if you select LJ_rgUNI5V (Unipolar 0-5V), the driver will actually tell the U6 to use the +/-10V range so you will not get an error.