Stepgeneration 2.6.6 vs 2.8.0

Well I have a been working through a PC failure and have found a few interesting things about the step generation on 2.6.6 and 2.8.0.

I wanted to give the new trajectory planner a whirl so I thought that I would install 2.8.0 and the step generation signal is around 50us vs the 3us from all previous versions. Here are the results from the same exact PC setup with Debian Wheezy running. The latency is ~11us in each case.

Here you can see the step signal in 2.6 is very normal.




Here you can see the step signal in 2.8 is not normal.




Anyone else testing version 2.8 and seen this issue?

Matt

A couple of things. Are you sure it is the same config? If you are not using the -reset function of the printer port (and stepgen’s doublefreq) you are only going to get a step every 2 base periods. (so that looks like your base period is 25us...)

I just ran master (and 2.7) and using the reset functionality I get around4us minimum step




(sorry for the analog that is 1us per dev)

What is the -reset function? Is it a setup config item?
Matt

Huh - thought I posted a link. I don't know if stepconf is aware of it..

linuxcnc.org/docs/devel/html/hal/paralle...ml#_using_doublestep

your 2.6 config must be using it - the 2.8 isn't would be my guess.

sam

I have just retested again and it is the same results.

Load 2.6.6 and create a new configuration with stepconfig wizard

~3us step pulse.

Load master - 2.8.0-pre1-485-g5165e754 and create a new configuration with stepconfig wizard. Need to generate new configuration as the 2.6.6 will not run in 2.8.0.

~50us step pulse.

Perhaps I do need to change something else i.e. -reset, but I have never had to do this before for stepconfig.

Matt

Here are the hal files. I see no difference in them for the port control.
Matt