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USB to Parallel Converter Reading Fault

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USB to Parallel Converter Reading Fault

Postby Dale » Fri Jul 22, 2005 1:41 pm

Hello,

I was in the process of testing a ADC22 with a USB converter and noticed the mv values i was indicating on the screen was different to that i was measuring on my multi meter.
On further investigation and hair pulling i connected to the ADC22 via the LPT port.
The value displayed was then the same as my multi meter.
If the value was 2400mV it would only be reprenesented as 2300mV via the USB adaptor but correctly using the LPT connection.
From a measuring range of 480mV to 2400mV the USB would represent this from 460mV to 2300mV and it seems linear.
The software is release 5.12.1 32Bit Version,
ADC11/22 USB driver is V4.2
PICOPP.SYS is V1.8
I have tried 2 ADC22, 2 USB, & 2 Computers (Different Version of software)but always the same results.
Any Idea's?

Regards

Dale.
Dale
 

Postby Sarah » Fri Jul 22, 2005 1:48 pm

Hi

Thank you for your post.

I have not heard of this happening before. I recommend that you try the latest version - 5.12.4 from our website http://www.picotech.com/software and see if the problem still presents.

Let me know how you get on with this.

Best Regards
Sarah
 

No Joy

Postby Dale » Fri Jul 22, 2005 3:40 pm

Sarah

No joy im afraid, and im definatley not going mad!

I have downloaded the latest software with no effect.

I have been veiwing all the data channels via the Recorder and have one channel configured for 2400mV. all the other channels are at 480mV
When i am connected via LPT 1 it is is displayed as 2400mV and 480mV.
When i am connected via USB it is is displayed as 2300mV and 460mV.
Have tried using a USB hub which has an external power source with no effect.

Any clues?

Dale.
Dale
 

Postby Sarah » Mon Jul 25, 2005 10:27 am

Hi

Thank you for your post and the update.

I have tried this out but so far have not really been able to replicate it. I have tried connected a battery to the ADC-22, on the LPT port if shows as 1.596V and on the USB as 1.591V. This difference is negligable and does not really count as an offset.

Would it be possible for you to send us a settings file for each of your setups so that we can try it here? Please send them to tech@picotech.com and I will try again to replicate this issue.

Best Regards
Sarah
 

Kinda cracked it..!

Postby Dale » Mon Jul 25, 2005 2:31 pm

Sarah,

There were no settings to be sent, but we had an older ADC22 knocking about and connected to it.
Via the LPT port we read 2.400Volts which was correct.
Via the USB port we read 2.400 Volts which was also correct.

The 2 brand new ADC22 units measured as I expressed on earlier posts.

Have the electronics changed in these unit recently?
Or do you think we mihgt have a 2 dodgy units from a batch?

Rgards,

Dale

PS there were no setting files, all we did was configure the Pico recorder software to look for device ADC22 via LPT1 or USB_PP1.
We then just configured a channel for monitoing and injected a known votage into it.
No scaling involved just the raw voltage displayed....!
Dale
 

Postby Sarah » Tue Jul 26, 2005 9:11 am

Hi Dale

As we discussed yesterday by telephone, please send these to us for us to look at.

Best Regards
Sarah
 

ADC-22 units

Postby Dale » Wed Aug 03, 2005 4:07 pm

Hello Sarah,

Was wondering if you have recieved my 2 ADC-22 units yet ?

Regards

Dale
Dale
 

Postby Sarah » Fri Aug 05, 2005 9:29 am

Hi Dale

Yes we do have your units. I will need to contact you with more information once I have spoken to my colleagues. If you could email us at tech@picotech.com then we will be able to update you via email.

Best Regards
Sarah
 


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