Re: STG2 Outputs

[JohnDRoc-at-aol.com]

Jon,

I think I may have a bad STG board.  When I run the diagnostics program that 
comes with the board, specifically the I/O test, it should read 1's across 
all 32 bits and then they should go to zero when grounded.  Mine doesn't; it 
starts out with mixed ones and zeros.  They don't switch when grounded, 
either.  This would explain the problem I was having with the MIN/MAX_Limits, 
too.  Even when I had the limits DI's grounded, I still got flip-flopping 
errors.  Completely unrelated to the DAC issue, or is it?  I tested all of 
the DAC outputs on the output op amps and they were all (-) except for DAC1.  
I spoke to Don Mclane at STG, and he said the DI test sounded suspect, as did 
the DAC problem.  (Since I had the Y axis running first (originally on DAC0), 
I copied the whole setup to the X axis, so I'm sure they're identical.)  In 
the interest of saving time, I am going to FedEx the board back to Don and 
let him verify that it does or doesn't work.  Looking at the STG board, 
several of the IC's appear to be "scuffed."  Perhaps this is a board that was 
supposed to have been scrapped and got shipped by mistake, or perhaps this is 
retribution for the stink I made when the first one took three weeks to 
overnight.  Oh well, here goes another three weeks....

-John