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QPX1200 ethernet comms

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

Dan
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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,

Dominic Walker
Cardiff University
Electrical and Electronic Engineering Student
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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

Dan
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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,

Dominic Walker
Cardiff University
Electrical and Electronic Engineering Student
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Dominic,

 

I am communicating with it via ethernet, not serial.

 

This button just brings up the same screen as is seen in MAX.

 

Dan

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DanB,

Does the device always respond with its identity, or just with the appropriate response to first command you send to it? 

 

Regards

Dominic Walker
Cardiff University
Electrical and Electronic Engineering Student
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Always the identity.
Dan
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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,

Dominic Walker
Cardiff University
Electrical and Electronic Engineering Student
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It still responds with its identity.
Dan
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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,

Message Edited by Dominic.Walker on 13-10-2009 01:37 PM
Dominic Walker
Cardiff University
Electrical and Electronic Engineering Student
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