EEPROM is modified, IR optocoupling is added.
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303181;image)
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303187;image)
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303193;image)
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303205;image)
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303199;image)
Protocol like this
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303211;image)
is decoded by Arduino to more or less normal view:
:-0.830 V DC
:-0.739 V DC
:-0.677 V DC
:-0.617 V DC
:-0.524 V DC
Now it is possible to use Labview easily to get data from DMM.
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303217;image)
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303223;image)
(https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921-again-with-arduino-and-labview/?action=dlattach;attach=1303229;image)