夏一宁 wrote: > hi,cal: > In my opinion,FPGA card seems to have little connection with Latency > thing. Generally speaking The PC system just give the FPGA card a > command,so how to send pulse (or voltage),and read encoder number is the > duty of FPGA itself.I think that will take little resource of PC.The Latency > is sth about the character of OS,(also too much work load may also affect > but obviously FPGA board NOT) > > Right, the "accelerator" card doesn't affect latency, but it changes the DEPENDENCE on latency. I have a different FPGA card, but the principle is mostly the same. If you are using software to generate step pulses, then you need some small number of microseconds of latency, or the step pulse timing will become quite ragged. By default, I update the external step pulse generator 1000 times a second. As long as the computer can service the external board within a millisecond, everything will stay smooth. So, even 100 us of latency will usually not cause horrible artifacts or cause steppers to stall.
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