10-08-2009 09:38 AM
Hi,
I'm trying to setup comms with the TTi QPX1200.
I can see the device in MAX, and communicate with it via its own web page.
Initially, I would like to be able to talk to it through the Instrument I/O Assistant. At the moment, the only command I can get it to respond to is *idn?.
Does anyone have any experience of communicating with this via LV?
Dan
10-12-2009 04:08 AM
Hi DanB,
If you can see the device in MAX, and it responds to '*idn?' this would suggest its all set up correctly, so ensure your using the correct synax. There are a list of commands for the TTi QPX1200 on page 24 of the manual found here: http://www.tti1.co.uk/downloads/manuals/QPX1200%20Instruction%20Manual%20-%20Iss%203.pdf
Remember these commands are case sensitive.
Please let me know if this solves your problem or not!
Kind regards,
10-12-2009 10:17 AM
Hi Dominic,
Thanks, I'm familiar with the commands listed in the user guide.
I've been doing a little more investigation. As mentioned before, the device shows up in MAX, and I am able to control it via its 'Web Page'. See the attached screenshot for the response to V1? (simply querying the output voltage) in the web page - this seems to be working fine.
Next, I tried to talk to it via the Instrument IO Assistant - first by sending *idn? (see respective screenshot), then by sending V1?. Interestingly, these both yielded the same response from the device.
Is it possible that the response to *idn? is sitting in a buffer somewhere (as a result of what MAX does to identify the instrument), and whenever the Instrument IO Assistant looks for a response, it just sees what is in this buffer?
Dan
10-13-2009 03:12 AM
Hey DanB,
Your right, it sounds like its filled up the buffer and it has not been cleared. Have you enabled the Xon/Xoff flow control? This should help to avoid buffer problems as the manual suggests the device uses it. Theres a screenshot attached below to show you where to find this option.
Let me know how you get on with it, and if it fixes the problem.
Regards,
10-13-2009 03:19 AM
Dominic,
I am communicating with it via ethernet, not serial.
This button just brings up the same screen as is seen in MAX.
Dan
10-13-2009 04:13 AM
DanB,
Does the device always respond with its identity, or just with the appropriate response to first command you send to it?
Regards
10-13-2009 04:19 AM
10-13-2009 04:39 AM
DanB,
If you can reset the device, and restart the computer, this should clear all the buffers. After this, initially query it with something other than '*IDN?', maybe 'ADDRESS?' or something similar.
Let me know if it still responds with its identity.
Thanks,
10-13-2009 05:14 AM
10-13-2009 07:36 AM - edited 10-13-2009 07:37 AM
DanB,
Have you tried not using the Instrument I/O Assistant? You can try using the low level visa functions, I've attached a simple VI below. (If you have a version before 2009 let me know and I'll save it in the relevant format).
Another option could be to install the manufacturers provided driver, which will give you pre-built VI's. The driver can be found at http://www.tti-test.com/go/qsx/qpx-downloads.htm and after installed you can find the VI's in Instrument I/O > Drivers > QPX on the functions palette.
Hopefully one of these will work, let me know!
Kind Regards,