spindle control of PM-728vt using linuxcnc

Has anyone added spindle control of the PM-728vt using Precision Mathews 0-10 speed control board?

Thanks
Jim

I have the mill running already with the mesa 7i76e.  I'm trying to add spindle control F/R in preparation for rigid tapping.
I already have the 0-10 volts figured out and working.  The issue is the F/R.  It should be simple but its giving me fits.

Thax
Jim

The Mesa card is powered with 24v
Mesa has TB4 designated for spindle control (see below )
     . With W4 installed outputs have weak pullups. Outputs (ENA+,ENA-,DIR)
        - verified state change with hal for ENA+ and ENA-
            . halcmd show pin hm2_7i76e.0.7i76e.0.0.output-08 then 07
      . 10v applied to TB4-pins (1,3)
     . Wiper TB4 pins (1,3) wired to PM pins (VIN,COM)
        - verified out changes (0-10v) with speed

Now for my total confusion!
If I wire TB4-ENA+ to PM-FWD with pulldown and TB4-spindle-(aka COM) to PM-3(aka COM) the
spindle run forwad with m3 s1000 it runs forward at 1000
.  If I issue m4 s1000 it also runs forward at 1000rpm

IF I wire TB4-ENA- to PM-REV with pulldown. spindle run reverse as well as forward per above.


Confused
Jim




##########################################################################################
Mesa 7i76e TB4 SPINDLE CONNECTOR
TB4 is the spindle drive interface with isolated analog output and control signals for
a spindle interface.TB4 is a 8 terminal 3.5 MM pluggable terminal block with supplied
removable screw terminal plugs.

TB4 PINOUT
1 SPINDLE-
2 SPINDLE OUT
3 SPINDLE+
4 NC
5 SPINDLE ENA-
6 SPINDLE ENA+
7 SPINDLE DIR-
##########################################################################################

##########################################################################################
Precision Mathes ( 0-10V Motor Speed Controller board  pinout )
Will reference as ( PM )

PM PINOUT
1 FWD     Forward
2 REV     Reverse
3 COM     Common
4 NC    No Connection
5 VIN    External 0~10V In
6 COM    To control speed
##########################################################################################
 

If grounding FWD results in forward motion and grounding REV results in reverse
motion _AND_ the PM FWD /REV inputs will accept +24V without damage

I would connect

7I76E OUT7 --> FWD and say 2K 1/2W pulldown resistor to PM pin 3 (COM)
7I76E OUT8 --> REV and say 2K 1/2W pulldown resistor to PM pin 3 (COM)

invert OUT7 and OUT8 in the hal file (since off means pulled down=active)
connect OUT7 to CW and OUT8 to CCW in hal file

There should be no connection to TB4 ENA or DIR pins


Another option if you wish to use TB4 ENA and DIR outputs is to add a small SPDT relay:

TB4 ENA- --> PM3 (COM)
TB4 ENA+ --> SPDT RELAY C
SPDT RELAY NO --> FWD
SPDT RELAY NC --> REV
SPDT RELAY COIL+ --> +24V
SPDT RELAY COIL- --> DIR+
TB4 DIR- --> 24VGND

(note that the relay needs a flyback diode across its coil, cathode to COIL+)

First test PM pin1 (FW) connected to PM pin 3(COM)
     - command m3 s400  Spindle turns CW at 400rpm
     - command m4 s400  Spindle turns CW at 400rpm    Why
Second test PM pin2 (REV) connected to PM pin3(COM)
     - command m4 s400 spindle turns CCW at 400rpm
     - command m3 s400 spindle turns CCW at 400rpm     Why?

Why does connecting eaither FW or REV seperatly  allow the same rotation when issuing both m3 and m4 to each.  This cant be right.

thank you
jim


 

Its not right

You need to assert FWD or  REV to the PM interface independently
Your current wiring does not allow this

You also need to get the polarity of FWD and REV correct

The required polarity and function of the FWD/REV inputs 
should be determined  before running LinuxCNC

Test 1 was run with only FW signal connected .
Test2 was run win only REV signal connected.

jim

FWD or REV connected to COM with a wire?