Step/Dir Servo Spindle Kicking My Butt - No Reverse

Are you referring to analog spindle control? Unless I'm missing something, it appears the 7i76e TB4 analog spindle control doesn't support negative voltages. That's why I switched over to step/dir spindle control, and have now encountered this M4 problem.

Thanks.

Mike Connelly wrote:

M4 seems broken in both Axis and Probe Basic. I was suspecting the UI since MDI and manual GUI buttons don't work, so wrote a short gcode program to turn the spindle on and off. M3 commands work fine, but M4 is still dead.
 

I think its more likely something with halui as my Axis config with no halui hooks works properly with m4

Any particular reason why you're using 2.10? I've been using the same servo drive with S+D for 2 years with 2.7 now 2.8.4 with gmoccapy. M4 works fine as does the UI manual reverse command. Your hal file looks fine, I assume you're bypassing the spindle PID for testing. I don't use a PID on the spindle at all.

As mentioned you might want to try disconnecting all the halui stuff. My config doesn't have any halui worth talking about connected to anything.

Also somebody mentioned using MAX_REVERSE_VELOCITY in your ini file in the other thread. You should probably try that, maybe there's a bug in 2.10 that needs it. My ini does not have it

2.10 is what was prescribed in the Probe Basic installation howto I followed, so I went with it.

Actually figured out the problem is MAX_REVERSE_VELOCITY and MIN_REVERSE_VELOCITY need to be explicitly set in the ini. Docs says they will default to MAX_VELOCITY and MIN_VELOCITY, but they don't.

M4 now works in LinuxCNC, but my servo turns the same direction for M3 and M4. Going to put the scope on PUL and DIR and see what's going on.

Thanks.

Before you bother with the scope you'll wanna check that spindle.0.speed-out-rps is a negative value when running in reverse. If not MAX_REVERSE_VELOCITY probably needs to be negative