How to switch between the A and A-B input for the sr830 lockin amplifier?

[Scandy]

Hallo,

I have a very simple and probably outdated question, but I really had a hard time finding anything on the internet, including the NI forums. 

I want to acquire data from the sr830 lockin amplifier. In the middle of one run I want to switch from the normal input (the A input on the front panel) to the differential voltage input (the A-B input on the front panel). The Sr830 manual says it should be possible:

ISRC (?) {i} The ISRC command sets or queries the input configuration. The parameter i selects A (i=0), A-B (i=1), I (1 MΩ) (i=2) or I (100 MΩ) (i=3).

But I'm not using this kind of code. I'm just using the Labview driver and its commands. I looked like 3 times through all of the commands (if you go like Instrument I/O -> Instr Drivers -> Standford Research 830) and couldn't find one that would configure this parameter. Which is odd, since I thought you should be able to control anything with Labview driver that you can control on the front panel.

I'm using Labview 2011 on Windows 7. 

Does anyone know a solution to this? Am I overlooking something?

Thank you for your help.

[nyc_(is_out_of_here)]

---

@Scandy wrote:

I want to acquire data from the sr830 lockin amplifier. In the middle of one run I want to switch from the normal input (the A input on the front panel) to the differential voltage input (the A-B input on the front panel). The Sr830 manual says it should be possible:

ISRC (?) {i} The ISRC command sets or queries the input configuration. The parameter i selects A (i=0), A-B (i=1), I (1 MΩ) (i=2) or I (100 MΩ) (i=3).

But I'm not using this kind of code. I'm just using the Labview driver and its commands

---

You are not using "this kind of code"????

I have news for you. You are.  What do you think is in the LabVIEW driver?

[Scandy]

Thank you for you reply.

I'm sorry for my ignorance. What I meant was that I don't see this code directly anywhere. I could easily believe the Labview Driver does use the code. The point is, I don't know neither how to access it directly nor how to implement this exact line. 

Is there a way to access the code? Open a console or something similar? I've been using Labview for some time and never knew that I could access a direct code anywhere. But again, it's a complicated program, and can easily believe I've only been on the surface thusfar.

Thank you again for your help.

[Dennis_Knutson]

You can open any VI you want and see the code. All of the commands that the instrument uses are clearly visible. You can edit the driver to add functions just like you would edit any other LabVIEW program.

What did you do to verify that the command is not in the current driver? Did you do a search? Did you run I/O Trace?

[Scandy]

You can open any VI you want and see the code. All of the commands that the instrument uses are clearly visible. You can edit the driver to add functions just like you would edit any other LabVIEW program.

I'm sorry for my ignorance, but how do I do that? I've always used Labview as a block diagram program. You open the diagram window with Ctrl+E, you choose the blocks you need and you wire them up together. By hovering over every block you can see his function description (using the Help mode with Ctrl+H). Is there another way to open vi's in a code mode?

What did you do to verify that the command is not in the current driver? Did you do a search? Did you run I/O Trace?

No, what I did was going through all the blocks in the VI-tree from the driver and checking their functions. None of them had a function to configure the A and A-B input mode, as far as I could see. How could I do a search or an I/O Trace?

Thank you again for your help and sorry for being such an outdated newbie.

[Dennis_Knutson]

The block diagram IS the code. The driver will have VISA/GPIB functions. That's pretty basic.

You have the search tool that can be selected for text. With the project in memory, you can do a search of all VIs for the commands. I/O Trace is a utility program you launch in MAX. It will capture all commands/responses that a program (such as an example) has.

No driver is perfect and may not be 100% complete. Adding the command is trivial.

[dmsilev · Accepted solution]

In the NI driver, it's the Configure/Configure Input Signal.vi routine; the Input Connection control. 

[Scandy]

Thank you so much, I completely overlooked that option.