[SOLVED] MesaCT problems with 7i96 pwm spindle

ahhh thanks pete!  i just came across that just a few minutes ago. i thought that looked suspect. must be a bug in jt’s config tool because thats straight out of mesaCT. 

quick question, any reason i cant get more than 4.45v out of my pwm?  ive checked everything on the hardware side and its all good there. no matter what i do, i cant get more than 4.45v max from the pwm

The STEP/DIR output voltage will be the 7I96 5V supply voltage
if there is no load. Any load will lower the output voltage.
So it could be low supply voltage, or a load on the output
The output resistance is around 50 Ohms so a 10 mA load will drop
the output voltage by about 0.5V

PCW wrote:

No outputs are GPIO

7I96 isolated output hal pins are:

hm2_7i96s.0.ssr.00.out-00
hm2_7i96s.0.ssr.00.out-01
hm2_7i96s.0.ssr.00.out-02
hm2_7i96s.0.ssr.00.out-03
hm2_7i96s.0.ssr.00.out-04
hm2_7i96s.0.ssr.00.out-05

 

Those are 7i96s output pins...

These are 7i96 output pins
     7  bit   IN          FALSE  hm2_7i96.0.ssr.00.out-00
     7  bit   IN          FALSE  hm2_7i96.0.ssr.00.out-01
     7  bit   IN          FALSE  hm2_7i96.0.ssr.00.out-02
     7  bit   IN          FALSE  hm2_7i96.0.ssr.00.out-03
     7  bit   IN          FALSE  hm2_7i96.0.ssr.00.out-04
     7  bit   IN          FALSE  hm2_7i96.0.ssr.00.out-05
and up the 7i96 outputs are using the wrong pins in MesaCT.

I'll fix that.
JT

Fixed the outputs and inverts for 7i95t, 7i96, 7i96s, 7i97 and 7i97t.

JT

Yeah, sorry, I copied them from a 7I96S halshow and forgot to delete the "s"

thanks jt, that was making me go bonkers trying track that one down. found that in one of my other machines configs and it worked!

as for the pwm voltages, i just got through checking everything and i shouldn’t have any load on the pwm at all. the 7i96 is powered with a dedicated 5v 0.55a psu. i adjusted the pot to 5.42v(i dare not go any more) and i get 5.31v between +5 and gnd and at 24k rpm which is max, i get same between gnd and pwm- when i have the cable to the vfd box disconnected. when i connect the cable it drops to 4.86v. is the converter actually pulling a load?  i can get close to 10v if i boost the input voltage to 14v which is within the range of the board, but is that just a hack or will that work?  or is the psu for the mesa board under powered? i saw that in a post that 250ma was enough without any loads.