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Author Topic: Need help with Viper servo drives  (Read 2365 times)

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Need help with Viper servo drives
« on: December 27, 2012, 07:40:25 AM »
I have been converting a YCM-30 and have reached the point of testing the encoders (US Digital E5 1000 CPR no index) but cannot get anything but 0000 from the M command in hyper terminal.  Upon investigation, I discovered 5v from the power supply pin (to the encoder) but also by accident about 4.6v on each of the A,B,A-,B- also (which definitely doesn't seem correct).  Anyone that can check their cards for this condition I would surely appreciate. 

I only have a few more days to be able to work on this conversion before I travel again for work, so any help right away would be greatly appreciated.  I called Larry Kenny but I think he may be off for the holidays.

Best regards,

Daryl Stamp
Re: Need help with Viper servo drives
« Reply #1 on: December 28, 2012, 02:45:37 AM »
Got feedback from Larry late yesterday,  normal to see just under 5v on each encoder input pin,  "There will be almost 5 volts on all the encoder inputs, because they have pullup resistors.."

Now I'm excited to dig into this again before the Grandkids wake up in the AM. 

Regards'
Re: Need help with Viper servo drives
« Reply #2 on: December 28, 2012, 12:20:11 PM »
Checked the encoders again this AM,  all working OK.   My own stupidity, errors that were the problem.
Re: Need help with Viper servo drives
« Reply #3 on: December 28, 2012, 07:14:20 PM »
have you added the ceramic cap to the 5v and ground at the encoder? the us digital units according to marris of gecko drives , do not have a bypass capacitor and can give an erratic output. i had problems with drive faults with the vipers that could not solve until adding the ceramic cap at the encoder. check out the gecko site. there is an instructional document for the fix of the us digital encoders. i have purchased some amt102 encoders with the line drivers  to replace them when i have time. the amt102 each with line driver cable were only about 40.00  .