7i80-DB + 7I76 - PWM Spindle ?

mjoconr
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7 years 3 months ago #139960 by mjoconr

Replied by mjoconr on topic 7i80-DB + 7I76 - PWM Spindle ?

So what is the best way of getting a PWM output ?

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PCW
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7 years 3 months ago #139961 by PCW

Replied by PCW on topic 7i80-DB + 7I76 - PWM Spindle ?

If slow PWM is OK (say 20 Hz), you could us software PWM, as pl7i92 suggested
and direct it to a field output or a unused stepgen output.

If you need faster (hardware ) PWM you would need a new 7I80DB-16 bitfile that
includes a PWMgen, probably on the last 7I76 step/dir pin set

I did find a manual for the BD1100 but its in Chinese and
doesnt seem to have much in the way of interface details
(if google translate did a decent job)

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PCW
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7 years 3 months ago #139965 by PCW

Replied by PCW on topic 7i80-DB + 7I76 - PWM Spindle ?

freeby.mesanet.com/7i80db_16_7i76x3D3p.bit

Bitfile for 7I80DB-16 with up to 3 7I76's
Each 7I76 has the last stepgen replaced with a pwmgen

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mjoconr
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7 years 3 months ago #139966 by mjoconr

Replied by mjoconr on topic 7i80-DB + 7I76 - PWM Spindle ?

That's cool, does this need the hal line configured as per my message from before ?

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PCW
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7 years 3 months ago #139975 by PCW

Replied by PCW on topic 7i80-DB + 7I76 - PWM Spindle ?

Yes, you would need to enable at least one pwmgen in the driver command line

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mjoconr
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7 years 3 months ago #140042 by mjoconr

Replied by mjoconr on topic 7i80-DB + 7I76 - PWM Spindle ?

So how would I change the following config to configure and connect the PWM to this.
Note I had to comment out and bypass the spindle gain as config as it caused a load error

Code:

loadrt [KINS]KINEMATICS
#autoconverted  trivkins
loadrt [EMCMOT]EMCMOT servo_period_nsec=[EMCMOT]SERVO_PERIOD num_joints=[KINS]JOINTS
loadrt hostmot2
loadrt hm2_eth board_ip="10.10.10.10" config=" num_encoders=1 num_pwmgens=1 num_stepgens=4 sserial_port_0=00xxxx"
setp   hm2_7i80.0.watchdog.timeout_ns 5000000
loadrt pid names=pid.x,pid.y,pid.z,pid.s

addf hm2_7i80.0.read          servo-thread
addf motion-command-handler   servo-thread
addf motion-controller        servo-thread
addf pid.x.do-pid-calcs       servo-thread
addf pid.y.do-pid-calcs       servo-thread
addf pid.z.do-pid-calcs       servo-thread
addf pid.s.do-pid-calcs       servo-thread
addf hm2_7i80.0.write         servo-thread

setp   pid.s.Pgain     [SPINDLE_9]P
setp   pid.s.Igain     [SPINDLE_9]I
setp   pid.s.Dgain     [SPINDLE_9]D
setp   pid.s.bias      [SPINDLE_9]BIAS
setp   pid.s.FF0       [SPINDLE_9]FF0
setp   pid.s.FF1       [SPINDLE_9]FF1
setp   pid.s.FF2       [SPINDLE_9]FF2
setp   pid.s.deadband  [SPINDLE_9]DEADBAND
setp   pid.s.maxoutput [SPINDLE_9]MAX_OUTPUT
setp   pid.s.error-previous-target true
setp   pid.s.maxerror .0005

net spindle-index-enable  <=> pid.s.index-enable
net spindle-enable        =>  pid.s.enable
net spindle-vel-cmd-rpm-abs     => pid.s.command
net spindle-vel-fb-rpm-abs      => pid.s.feedback
net spindle-output        <=  pid.s.output

# ---digital potentionmeter output signals/setup---

setp   hm2_7i80.0.7i76.0.0.spinout-minlim    [SPINDLE_9]OUTPUT_MIN_LIMIT
setp   hm2_7i80.0.7i76.0.0.spinout-maxlim    [SPINDLE_9]OUTPUT_MAX_LIMIT
setp   hm2_7i80.0.7i76.0.0.spinout-scalemax  [SPINDLE_9]OUTPUT_SCALE

#net spindle-vel-cmd-abs     => hm2_7i80.0.7i76.0.0.spinout
net spindle-vel-cmd-rpm-abs     => hm2_7i80.0.7i76.0.0.spinout
net machine-is-enabled      => hm2_7i80.0.7i76.0.0.spinena
net spindle-ccw         => hm2_7i80.0.7i76.0.0.spindir

# ---Encoder feedback signals/setup---

setp    hm2_7i80.0.encoder.00.counter-mode 1
setp    hm2_7i80.0.encoder.00.filter 1
setp    hm2_7i80.0.encoder.00.index-invert 0
setp    hm2_7i80.0.encoder.00.index-mask 0
setp    hm2_7i80.0.encoder.00.index-mask-invert 0
setp    hm2_7i80.0.encoder.00.scale  [SPINDLE_9]ENCODER_SCALE

net spindle-revs             <=   hm2_7i80.0.encoder.00.position
net spindle-vel-fb-rps       <=   hm2_7i80.0.encoder.00.velocity
net spindle-index-enable     <=>  hm2_7i80.0.encoder.00.index-enable

# ---setup spindle control signals---

net spindle-vel-cmd-rps        <=  spindle.0.speed-out-rps
net spindle-vel-cmd-rps-abs    <=  spindle.0.speed-out-rps-abs
net spindle-vel-cmd-rpm        <=  spindle.0.speed-out
net spindle-vel-cmd-rpm-abs    <=  spindle.0.speed-out-abs
net spindle-enable             <=  spindle.0.on
net spindle-cw                 <=  spindle.0.forward
net spindle-ccw                <=  spindle.0.reverse
net spindle-brake              <=  spindle.0.brake
net spindle-revs               =>  spindle.0.revs
net spindle-at-speed           =>  spindle.0.at-speed
net spindle-vel-fb-rps         =>  spindle.0.speed-in
net spindle-index-enable      <=>  spindle.0.index-enable

# ---Setup spindle at speed signals---

sets spindle-at-speed true

#  Use ACTUAL spindle velocity from spindle encoder
#  spindle-velocity bounces around so we filter it with lowpass
#  spindle-velocity is signed so we use absolute component to remove sign
#  ACTUAL velocity is in RPS not RPM so we scale it.

#setp     scale.spindle.gain 60
#setp     lowpass.spindle.gain 1.000000
#net spindle-vel-fb-rps        =>     scale.spindle.in
#net spindle-fb-rpm               scale.spindle.out       =>   abs.spindle.in
#net spindle-fb-rpm-abs           abs.spindle.out         =>   lowpass.spindle.in
#net spindle-fb-rpm-abs-filtered  lowpass.spindle.out

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andypugh
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7 years 3 months ago #140582 by andypugh

Replied by andypugh on topic 7i80-DB + 7I76 - PWM Spindle ?

Probably change

Code:

net spindle-vel-cmd-rpm-abs     => hm2_7i80.0.7i76.0.0.spinout

Code:

net spindle-vel-cmd-rpm-abs     => hm2_7i80.0.7i76.0.0.pwmgen.00.value

linuxcnc.org/docs/2.7/html/man/man9/hostmot2.9.html#pwmgen
You will also need to enable the pwmgen and set the scale using the appropriate pins.

Have you flashed the new firmware?

You can get a list of the actual pin names by typing this at the command line. (You might recognise some of it)

Code:

halrun
loadrt hostmot2
loadrt hm2_eth board_ip="10.10.10.10" config=" num_encoders=1 num_pwmgens=1 num_stepgens=4 sserial_port_0=00xxxx"
show pin
show param
show funct
exit

Copy and paste the output to a text file for reference

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mjoconr
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7 years 3 months ago #140601 by mjoconr

Replied by mjoconr on topic 7i80-DB + 7I76 - PWM Spindle ?

Thanks Andy

Yes I've flashed the firmware and updated the hal with the correct loadrt.

I do recognise the commands, but did not know I could do this by hand. Very useful.

Thanks for the reference page for the pwmgen.

Will take a little testing to work out what the frequency should be.

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mjoconr
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6 years 11 months ago #150406 by mjoconr

Replied by mjoconr on topic 7i80-DB + 7I76 - PWM Spindle ?

Hi All
Just wanted to update on this issue. The firmware provided by PCW worked a treat.
There is an issue with the direction ie I can only go M3 not M4, I'm assuming I got the wiring messed up but did not have time to check with a multimeter.
Did find out the drive sends out rotation pulse so I'm going to see if I can get LinuxCNC to estimate the RPM and feed this back in to a control loop. (might need help in another topic with this)

Thanks

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PCW
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6 years 11 months ago #150421 by PCW

Replied by PCW on topic 7i80-DB + 7I76 - PWM Spindle ?

The 7i80db_16_7i76x3D3p.bit firmware leaves the PWMs direction pins unconnected
I did this because if you don't need the direction pin, its free for general purpose use
and if you do need it, you can generate a direction signal in hal and drive the proper GPIO bit

7i80db_16_7i76x3D3p.bits PWM direction pins (wired to DIR4 on all 7I76s) are
on GPIOs 08, 25,42 for the first,second and third 7I76

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