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cannot communicate

Forum for discussing PicoScope (version 5)

cannot communicate

Postby ims » Mon Jun 13, 2005 8:13 pm

I am using the pico3206 and i am reciving an error message that says cannot comunicate with oscope. It happens every now and again, the same thing happens when i used the older model. My application uses two transducers in the through transmition mode. The input comes from a JSR ultrasonic DPR 300. The only time i get the error is when the application is running and i try to change transducers. Its is nessesary that i change transducers while the application is running so is there anything i can do to stop this problem.
ims
 

Postby Sarah » Tue Jun 14, 2005 9:40 am

Hi

Thank you for your post, I am sorry to hear that you have been seeing problems.

This error normally occurs when the software loses contact with the unit - ie if the USB cable has come unplugged. The other thing that could cause it is a lack of power to the device. Try plugging the unit in to the mains and see if this helps. It could be that the USB port is not able to supply quite sufficient power at all times.

Hope this helps

Best Regards
Sarah
 

Noise

Postby IMS » Tue Jun 14, 2005 1:18 pm

Thank you very much for you reply. I tried the suggestion and still the Pico scope will freeze up whenever I try to change transducers on my ultrasonic JSR. Even when I have the JSR off and play with the transducers I will get a large amount of noise which is ok for my application but I cant have the picotech freezing up on me in the middle. I have a feeling that the problem has something to do with a fault protection on the Pico scope for high voltage spikes, but I am no expert. Is there anything else I can try.

Thanks again you guys are great in responding.
IMS
 

Postby IMS » Tue Jun 14, 2005 1:40 pm

I just realized that the picoscope is completely turning off sometimes.
IMS
 

Postby Sarah » Thu Jun 16, 2005 10:39 am

Hi

Thank you for your post.

The Oscilloscope does have fuses on the inputs to protect against some voltage spikes. Is it likely that the input you are supplying is giving some kind of over-voltage at any point? This could be tripping a fuse, which later resets.

Does the scope freeze if you do not have the transducer connected?

Best Regards
Sarah
 

ok

Postby ims » Thu Jun 16, 2005 8:28 pm

I think the fuses are tripping b/c it will turn off then we have to unplug it and wait a bit before we can turn it back on. So if you could be my savior and give me a suggestion on an easy way to prevent these spikes on the pico end, I will fly to the U.K. and kiss the ground you walk on for being so wonderfully helpful.

O also we are using a 50 ohm terminator on the input to the pico, due to the specifications of the jsr manufacture.
ims
 

Postby ims » Fri Jun 17, 2005 2:42 pm

What is the voltage level that the fuses trip at b/c i could buy a voltage regulator that prevents that from happaning.
ims
 

Postby Sarah » Tue Jun 21, 2005 1:13 pm

Hi

Thank you for your post.

The only advice I can really give is to not let the voltage input exceed ±20V - this is the limit of the channels. Anything above this could trip the fuses.

Hope this helps

Best Regards
Sarah
 


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