On 02/02/2016 01:07 PM, Marius Alksnys wrote: > How would you explain that when parallel port transfers data 8 bytes at > a time and I get errors only in one bit through 3 bytes at least? > > As Peter says, the counters on the board are 16 bits. if the highest bit is read incorrectly, then the wider value handled by the LinuxCNC driver could trigger the carry/borrow logic, and produce this exact result. Incorrect reads of lesser-significant bits would cause transient jumps that would return to the right value on the next servo cycle. These should be easily seen in Halscope traces. But, if the error causes the carry/borrow logic, it will result in a permanent shift in the position as kept by LinuxCNC.
(I saw the same thing on my system several months ago, and traced it to a bad solder joint on the DB-25 connector.) Jon ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
