Sending signal via Ni USB 6225 and BNC 2115

[Taytwo]

Hi,

I have been trying to send a signal via a NI USB 6225 to a specific channel of a BNC 2115 (with 24 output channels) by using simulink. I am able to select the device on the analog output box in my simulink model but I can select just 2 outputs (the outputs of the NI USB 6225). How can I select a specific channel of my BNC 2115 to send the signal through?

Also, I tried to check if my BNC 2115 where working correctly by using a signal generator and by sending a sinusoidal wave to a channel but the signal is recorded on all channel of the BNC 2115 and not just the one really connected with a BNC cable to the signal generator. Someone know why I am having this issue?

Thank you very much for your help!!!

[algarcia]

Hi,

Since your device has 2 specific analog outputs, you'll only be able to make the connection to the corresponding BNC connections.

Why are you wanting to route the signal to another BNC connection?

You can route counter signals to different BNC connections from the following documentation:

Internally Routing Counter Signals in LabVIEW

http://digital.ni.com/public.nsf/allkb/8A85E97855EDADC98625730C00065F58

This is written in LabVIEW, but you should be able to make your corresponding function calls.

Regards,

[Taytwo]

Hi Algarcia,

Thank you for your answer. I guess I didn't give enough details in my previous message (because my English is also not really good...)

So I have a NI USB 6225 with 2 ports (not BNC ports) that I can connect to 2 BNC 2115 who each have 24 analog outputs). The NI USB 6225 are supposed to be able to send differents signlas as they have an entry with 1-16 ports and another 17-79 ports. My only concerns is that I would like to send different signals from the computer via the NI USB 6225 to the BNC 2115, nut in simulink I don't know how to have more than two ports (or if I can send a matrix in one port that will send different array in the different channels of the BNC 2115. I am not sure if it is clear?

Thank you,

Taytwo

[algarcia]

Hi Taytwo,

From looking at the data sheet, you only have access to 2 Analog Outputs from the NI USB 6225. Just because there are a lot more labelled on the BNC 2115 doesn't mean that you have access to them. The BNC 2115 is compatible with many devices and some of them have a lot of Analog Output channels; the BNC 2115 can only use what is on the USB 6225.

Additionally I don't have any experience with 3rd party software, but based on the data sheet, you should only have access to two ports.

Best

[Taytwo]

Hi Algarcia,

Thank you again for your quick reply. I am still not sure to understand. I know that I have only two ports on the USB 6225. However, when I used them as inputs and not outputs, I am able on the computer to record signals coming from all the different channels of the BNC 2115 (via the NI USB 6225) so I guess there is a way to access these different channels. My problem is that I am not able to send a signal to these channel via the NI USB 6225. It is why I was thinking that it is possible but I just don't know how to do it in simulink (or labview), meaning if I need to send like a matrix and it will make the association automatically to the different channels or something like that? Maybe it is just not possible, it seems just strange that I am able to record all the BNC channels at the same time in input even if there is still just 2 ports on the USB 6225, but I am not able to send signal through them.

Not sure I am making any sense...sorry

Taytwo

[JensG69 · Accepted solution]

Have a look at the manuals of the USB-6225 (Fig. 10 on Page 20) and the BNC-2115 (Table 5, Page 9).

When you connect Connector 1 (AI 16-79) with your BNC-2115, you'll get a direct connection from your 24 BNC-sockets of the 2115 to the analog-in-pins of the USB-6225.

Combine the informations of Fig. 10 and Table 5 (mentioned above) and you'll get a routing Pin-Number (68-pin) connector USB-6225 to the pin-numbers of the BNC-2115. That routing is FIXED by the connector cable.

Example: BNC-center Pin AI16 of BNC-2115 is connected to pin-no. 68 of connector 1.

Now: if your connect your BNC-2115 to connector 0 of your USB-6225 (BTW, that's not recommended to do, see here: Quote: Interfaces to connector 1 of 6225 M series devices), then the pin-outs of the two analog-out channels will be hardwired to:

AO 0 = Pin 22 of 6225 -> AI GND of 2115

AO 1 = Pin 21 of 6225 -> BNC Outer Shield AI-44 of 2115

AO Gnd = Pins 54 & 55 of 6225 -> AI 36 and AI 45 of 2115

So again:

Your 6225 has two analog-out channels, regardless of what is written on the BNC-2115.

and more important:

The BNC-2115 is NOT compatible with the USB-6225 when you connect it to "connector 0" of your USB-6225.

Regards, Jens

[Taytwo]

Hi Jens,

Thank you very much for your detailled reply. It make much more sense why I can't send more than 2 outputs via the NI USB 6225. I have a last questions. Do you know if National Instrument is selling a box (like the NI USB 6225 but in the opposite way) with a lot of AO and not too much AI?

Thank you again,

Taytwo

[JensG69]

Call your local NI representative and discuss your requirements and options with NI.

Regards, Jens

[Taytwo]

Yes you are right, I will do it.

Thank you again for your time!!!

Taytwo