1. Disclaimer
LinuxCNC

Disclaimer

This information HAS errors and is made available WITHOUT ANY WARRANTY OF ANY KIND and without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. It is not permissible to be read by anyone who has ever met a lawyer or attorney. Use is confined to Engineers with more than 370 course hours of engineering.

LinuxCNC

Installing under buster - for mesa

sources.list lines:

deb     http://buildbot.linuxcnc.org/ buster master-rtpreempt
deb-src http://buildbot.linuxcnc.org/ buster master-rtpreempt

Do not use RTAI real time kernel! - use Preempt-RT (pae PREEMPT_RT ) - install linux-image-rt-amd64

Linux Command line

Add isolcpus=2,3 ???

Disable cstates in the BIOS/ kernel command line - intel_idle.max_cstate=0 ??

LinuxCNC acronyms, abbreviations, special terms, file-types

BLDC - BrushLess DC [motor]
Comp - hal compiler tool
EMCIO - module of linuxcnc for non aixs i/o
EMCMOT module of LinuxCNC that handles the actual motion of the cutting tool.

hmid - HostMot ID (references the IDROM in HostMot2 firmware) IDROM specifies what features are included in a specific bitfile and the functions of the I/O pins
(hmid = Host Mot (Host Motion) ID = Host based Motion Control -- as in Ethernet host )
hal - Hardware Abstraction Layer - not to be confused with the old linux hal system of the same name.
ihs - Initial Height Sense
MDI Manual Data Input
NML(Neutral Message Language) - not sure - not in use?
sserial - Smart Serial

Special terms

joint - A joint is one of the movable parts of the machine. not to be confused with axis.
Kinematics - relationship between world coordinates and joint coordinates of a machine. There are two types of kinematics. Forward kinematics is used to calculate world coordinates from joint coordinates. Inverse kinematics is used for exactly the opposite purpose.
pin -

File-types

ini - this file normally named machine-name.ini It is the base file that points to all the other config files. LinuxCNC on start up looks for ini file found in a directory in ~/ linuxcnc/configs/machine-name
pncconf one directory up ls
vhd - vhdl file???
xise - files are Xilinx ISE project files - not really LinuxCNC related
ucf - ucf files are pin constraint files for Xilinx ISE
pin .pin files are text representations of the IDROM content
bit - bitfile used by mesaflash - binary configuration files for Xilinx FPGAs

Create Ethernet connection to Mesa card (this example used i793)

Set your jumpers so you are in the Default mode ( 7I93 W4 and W3 down ) - this will come up with the default IP address 192.168.1.121
You will need mesaflash installed. Linuxcnc must NOT be running.
First set the NIC to use 192.168.1.240 by creating
/etc/network/interfaces.d/local
With contents:

#linuxCNC mesa interface
 auto [your-mesa-NIC-device-name]
iface [your-mesa-NIC-device-name] inet static
address 192.168.1.240/24
# If using intel ethernet that in some cases looses the connection you might need
# hardware−irq−coalesce−rx−usecs 0

Then do
$ ifup your-mesa-NIC-device-name

If the other interface is using the common 192.168.1.0/24 network, you will probably need to shut it down temporarily with

$ifdown [your-other-NIC-device-name]

testing:

With the 7I93 powered and connected to the Ethernet device used above, try to ping 192.168.1.121

Then try

mesaflash --verbose --device 7i93 --addr 192.168.1.121

You should get some nice information back - you now should have Ethernet communications with the mesa card.

Change IP to non LAN network

In this example, we avoid the common 192.168.1.0/24 network by setting the Mesa card to 192.168.10.10 and the NIC to 192.168.10.1 both will use the 192.168.10.0/24 network address space :

$ mesaflash --verbose --device 7i93 --set ip=192.168.10.10

Look at the output - verify that space 2 has ip address: 192.168.10.10
This is now the IP address for the FIXED FROM EEPROM or non DEFAULT mode - ONLY (DEFAULT mode IP stays the same).
It is time to powerdown and change the W3 jumper to 'up' to set the card to use FIXED From Eprom mode.
Power the card back up.

Update /etc/network/interfaces.d/local

#linuxCNC mesa interface
 auto [your-NIC-device-name]
iface [your-NIC-device-name] inet static
address 192.168.10.1/24
# address 192.168.1.240/24
# If using intel ethernet that in some cases looses the connection you might need
# hardware−irq−coalesce−rx−usecs 0

Clear the arp cache and restart networking

$ ip -s -s neigh flush all 
$ systemctl restart networking

Test again - with

mesaflash --verbose --device 7i93 --addr 192.168.10.10

Write bit file to mesa card

This example assumes 7i93_svss4_8d.bit firmware would be appropriate

This file is not found in a zip file from Mesa - not in a Deb package.

$ mesaflash --addr 192.168.10.10 --device 7i93 --write 7i93_svss4_8d.bit

Should write and auto verify -

--$ mesaflash --addr 192.168.10.10 --device 7i93 --reload

If using intel ethernet that in some cases looses the connection, there should be the following line added in a terminal? ??

sudo ethtool -C eth0 rx-usecs 0

mesaflash syntax:

$ measaflash --help

Do not confuse --serial with --sserial
--verbose is your friend

List pins of the 7i29

$ mesaflash --device 7i93 --addr 192.168.10.10 --readhmid

information about all sserial remote boards

$ mesaflash --verbose --device 7i93 --addr 192.168.10.10 --sserial

Get pins of a mesa board:

$ halcmd show all |grep 7i84

Mesa config wizard

See http://linuxcnc.org/docs/html/config/pncconf.html

Computer response time -- Check for SMI (Slimy Management Engine) problems - 120 seconds - ( change to 3600 - or even more )

$ perf stat -a -A --smi-cost -- sleep 120

The management engine is why LinuxCNC does not do well on many brand new computers. Keep an eye out for coreboot compatibility - current status is not good(2020).

HP Compaq Elite 8300 Base Model Convertible Minitower PC jitter measurement :
Max 1,005,664 - jit 5920
Base 33,517 jit 8517

Connection to 7i84D vis 7i44

Mode is set via sserial_port_0=00000000 - 0 = mode-0 , 1 = mode-1 for details see $ man hostmot2

7i29 notes

CR13 and CR14 light when it starts overriding the duty-cycle to current limit.
It is possible to home by hitting a mechanical limit (at the very lowest speed) which would trigger a following error. Move back a mm and call it home. more at https://www.forum.linuxcnc.org/27-driver-boards/39589-7i29-amp-fault-output-pins
Always use differential encoders" (RS422)

Encoder notes

Index-mask - hardware input that masks the index input signal

INI file notes

1 machine unit = 1 LINEAR_UNITS as set in the [TRAJ] section

hal file notes

Some component instances are generated by things in the ini file.

Nomenclature

Component - software Object?
Parameter - variables - set on instance at startup of component
hal-pin a feature of a component?
signal - equate

Syntax

setp - set pin or parameter
sets - set value of signal
net - connects signal to pin(s) - names signal
unlinkp - disconnect pin from signal

Components

Components all are supposed to have their own man page for pin descriptions
inihal

iocontrol and halui (they seem to have overlapping functions)

estop pins

described assuming no pins are yet interconnected:

iocontrol.0.emc-enable-in -- sets the Estop button displayed in Axis - and
from the docs "Should be driven FALSE when an external estop condition exists."
(False is the 'in' position)

iocontrol.0.user-enable-out becomes the OPPOSITE of iocontrol.0.emc-enable-in if you click on the etop-button - Does NOT change the appearance of the GUI estop button.
From the docs "FALSE when an internal estop condition exists" (what defines an estop condition here? Are there other things that can trigger an estop? ) This appears to be the inverse of halui.estop.is-activated

iocontrol.0.user-request-enable iocontrol.0.user-request-enable ( output that 'PULSES' true if you click on estop button in axis AND iocontrol.0.emc-enable-in is false (pulses on pulling-out the GUI estop )
(iocontrol.0.user-request-enable is not completely documented in the man page (2020))

There is a way (by writing a component) to latch iocontrol.0.user-request-enable. That being said - it is an extremely bad idea to use this to enable a physical estop circuit - which one should setup a way to disable the physical estop from linuxcnc - but NOT enable it.

halui.estop.activate on rising edge activates halui.estop.is-activated
halui.estop.reset on rising edge resets halui.estop.is-activated

halui.estop levels won't prevent one from overriding with the axis button.

Machine on-off

halui.machine.is-on ==>
halui.machine.off <==
halui.machine.on <==

Motion - accepts NML motion commands, interacts with HAL in realtime

spindle.M.speed-out OUT FLOAT - Desired spindle speed in rotations per minute From g-code S100 command.

All the spindle.M.speed-out.xxx come from g-code (Sxxx).

wj200_vfd

I am told that the cheap RS232 - to - RS485 converters steal power from RTS and CTS so you might need to set them or use an external power-supply for reliable operation.

First, you will want to find the page B-4 in the wj200 manual and set A001, A002, C071, C072, C074, C075, C076, C077, and C078. Then install mbpoll and test for basic modbus communications

$ mbpoll -a1 -Pnone -d8 -b115200 -r1 -c4 /dev/ttyS0

You should see something like this

-- Polling slave 1... Ctrl-C to stop)
[1]:    0
[2]:    0
[3]:    2
[4]:    0

Note that the driver is loaded with wj200_vfd but the pin names follow the HAL convention and use wj200-vfd

wj200 defaults to --device=/devS0 --parity none --databits 8 --stopbits 1 --baud 9600

limit2 component

Keeps a float value between min and max - and dx/t under maxv

PID loop position

Some basics

Error = command - measured

Output = Error * PGain + (Integral of Error) * IGain + dError/dt * DGain + FF0 * command + FF1 * dCommand/dt

Where - FF1 is velocity-feedforward

output = bias + (pgain * tmp1) + (igain * error_i) + (dgain * error_d);
output += (command * FF0gain) + (cmd_d * FF1gain) + (cmd_dd * FF2gain);

,.,.
FF0 adds a portion of the command to the output (minimize error build up - best guess without feedback) normally set to o
FF1 adds a portion the first derivative of the command to the output (compensates for friction or Motor CEMF ) Normally set to 1 - adjust output scale so it is true.
FF2 adds a portion of the second derivative of the command to the output (proportional to acceleration thus a command that is increasing speed might need a bit of and extra kick to overcome inertia)
FF3 third derivative -- proportional to jerk (Change in acceleration )

MIN_FERROR = 1.0 amount of following error (distance in machine units) allowed at very low velocity
FERROR = 10.0 distance allowed during rapid moves. - permitted Ferrors are interpolated between these two numbers for speed.
H-bridge Tuning - Servo loop

What is PID?

PID loops are used in all sorts of systems, from temperature control, to advanced pressure regulators.

P - is Proportional feedback - it takes the error times a constant and adds it to the drive output. It is similar to the corrections one makes with the gas pedal of a car - if we are going a bit too slow, we don't floor it, we just press a proportional bit harder depending on the magnitude of the error. The original proportional only controllers go back to Huygens pendulums and latter Watts flying balls. The math behind all this was first explored by non other than James Clerk Maxwell in 1868

I - is Integral feedback - it takes the average error over time times a constant - and adds it to the drive output ( improves fine accuracy)

D - Is Derivative feedback - it takes the change in error times a constant and adds it to the drive output ( reduces errors when the load suddenly changes)

Understanding Feedforward

While P(proportional) feed-back works - if you turn it up very high, it will oscillate - same with D - same with I. So what would be good is if we can give a drive value that is close to what is needed and use PID for fine corrections of error. So for any change in motion - d/dt - we want a value to send that should give something close to the correct response - that is called feedforward.

This brings us to OUTPUT_SCALE which should be set to the speed obtained by giving full output to the drive. Thus a motion request scaled to OUTPUT_SCALE should get us close to the correct output. If OUTPUT_SCALE is correct, FF1 should equal 1. This adds to the output value a pretty good guess to what it should be - and the PID section looks at any errors and sends correcting additions or subtractions to the output.

Tuning Proceedure

This assumes you already know how to use the calibrate command - and HALscope.

Set DEADBAND to 1 machine resolution step * 0.6
Start with P, I and D FF0 and FF2 at zero
Set jog speed to 50 mm/min - know where your PHYSICAL ESTOP switch is and be sure it works - be ready to press it.
FF1=1 and increase P slowly so things can move - verify direction, limits, and homing.
Set P to low value - about 1/4 any possible oscillation. Oscillations can allso be caused by OUTPUT_SCALE being way off.
Set OUTPUT_SCALE to encoder.N.velocity when pwmgen is pedal-to-the-metal. We are finding the maximum speed the table can move! This means changing things in ini so you can move things at dangerous speeds - work smart - this is dangerous - if you don't know exactly what you are doing - don't )

If you are OK with the danger - for the axis under tuning you will need to temporarily greatly increase FERROR, MAX_VELOCITY. In the [DISPLAY] section set MAX_LINEAR_VELOCITY to something insane. (I could not change this via the calibration window - had to edit the ini file and restart)

MAX_ACCELERATION - plot the velocity feedback in Halscope and max out acceleration. The slope of that will be the physical max - you will want to set to something like 90% of this (Perhaps a bunch less? No reason to hotrod..)(MAX_ACCELERATION has to be correct for tuning to work - if you ask a PID loop to accelerate things faster than possible - the numbers saturate and clip).
Getting FF1 correct and accurate is key - other things won't work if it is wrong. It will be correct if you measure - no guessing.
Be sure jog speed is quite low - start with 50mm/min
Set up the HALscope to look at f-error, motor-pos-command, and pos-relative for the axis you are working on.
Start up the Calibrate window.
Increase P slowly until you get a slight overshoot - something that looks like a damping factor of 0.4-0.7 - increase jog speed.
Double the jog speed and repeat the step above. - keep doubling until you get to something like 1000mm/min
FF1 - Start with a very low number - 0.01 Increase slowly - Tune to eliminate start and stop over/under shoots (about 0.005% of P).
Set FF2 so that the actual position does not lead or lag the commanded position during acceleration
Increase I until you start to see oscilations in FERROR

Once this tuning is finished - set [TRAJ]MAX_LINEAR_VELOCITY approx 20% higher than the axis settings.

G-code is sort of ignorant of acceleration - one would want to set MAX_ACCELERATION to something sane.

Don't forget to return FERROR, MAX_VELOCITYt MAX_LINEAR_VELOCITY to operating settings.

Checks - compare pwmgen.N.scale to OUTPUT_SCALE

DCBM DC Brushed Motors

A DC motor gets a speed from this equation where ω is the rotation in radians:

ω = V/k - TR/k^2

k and R are constants - but k in the torque term it is squared so less of a factor (torque load slows things down a bit) so I see this as mostly a velocity input device. The slowing of the speed by tool force has to be corrected by the PID loop. We test at full posible speed to find OUTPUT_SCALE so that the second term of the above equation is insignificant.

speed for the test?

buzzyness?

increase P speed? damping?

Set D below buzzyness - ( a few wiggles in f-error plot ? )
Set FF1 so that the actual position does not lead or lag the commanded position at full speed
Set FF2 so that the actual position does not lead or lag the commanded position during acceleration
Increase P as much as possible without causing overshoot
Increase I below but close to instability. No slow hunting oscillations..

Changing PID values with Axis Machine/Calibration

This window makes temporary live changes of PID parameters - that you enter - after you press 'test'. One has to press Test - try the setting - then press Cancel to make the next change - rinse - repeat..
While in test - one has to create the move via Jog. Normally you would monitor joint.N.f-error with the halscope...

Manual tuning

Set I and D to zero - set P to 1/2 value where it starts to oscillate ( overdamped - no overshoot )
Increase I to instability - set to 1/2
increase D to instability - set to 1/2

Ziegler–Nichols method

https://en.wikipedia.org/wiki/Ziegler%E2%80%93Nichols_method

FF1, its the most important tuning number for velocity mode drives
Before tuning - remove all the PID maxerror lines in the hal file ..

FF1 should be set to within 1/10 1%

For a velocity mode servo (when the drive is tuned properly) D is _not_ appropriate and FF1 is arguably the most important tuning parameter.

Velocity vs torque mode tuning

They are NOT the same - so two subsections below

For both modes -
If OUTPUT_SCALE is set so PID output is in machine units per second then the PID values are "normalized" so inch and mm machines will have comparable PID numbers and things
like FF1 will make sense (FF1 will be 1.00 if the scaling is correct). Watch pwmgen.N.value and encoder.N.velocity with the halmeter and change OUTPUT_SCALE until they are close to matching.

For spindles

Torque Tuning

Start with FF1=0 and FF2 = 0 and I=0

Chose a small amount of P (say 50 = full torque with 1/5" error)
Then increase D until it gets too "buzzy" and then back off about 30% on D
Then increase P until you get oscillations and again back off about 30%
Then adjust FF2 so that you neither overshoot or undershoot during
acceleration (the FF2 setting is inertia dependent so its better to do this with a typical table load)
Finally increase I until motion becomes unstable (Watch out for WIDE oscillations here)
and back off about 50%

Another take - Increase D to oscillation - then set at 1/2
Increase P to oscillation - then set to 1/2
Add FF2 to tune out accel-undershoot - and decel-overshoot.
Carefully - add I to oscillation - then set at 1/4

Velocity tuning

For a velocty PID loop probably the most important part is FF0

If the PID feedback, command and output are all in RPM, FF0 should be 1.0)

If you have only FF0(all other PID terms=0), you are running open loop
(because the PID output is just FF0*Command)

Using the FF0 feedforward term make the PID output approximately correct before any
feedpack is applied. This makes the P and I terms have less work to do...

Links

http://support.motioneng.com/Downloads-Notes/Tuning/default.htm

Servo tunning: https://forum.linuxcnc.org/10-advanced-configuration/32367-servo-tuning-detailed-how-to
https://gnipsel.com/linuxcnc/tuning/servo.html

Spindle

# set the encoder to non-quadrature simple counting using A only.
setp hm2_7i93.0.encoder.04.counter-mode true

G33 centric -

spindle.N.at-speed

motion.coord-error OUT BIT TRUE when motion has encountered an error, such as exceeding a soft limit

motion.coord-mode OUT BIT

spindle.N.revs

spindle.0.speed-out-abs comes from g-code s command..

wj200-vfd.0.commanded-frequency sets motor speed..

- two speeds thus hm2_7i93.0.encoder.04.scale set via mux2

# set the HAL encoder to 60 pulses per revolution.
setp hm2_5i25.0.encoder.02.scale 400

# set the encoder to quadrature counting using A and B .
setp hm2_5i25.0.encoder.02.counter-mode false

# connect the HAL encoder outputs to LinuxCNC.
#net spindle-position-soft encoder.0.position => motion.spindle-revs
net spindle-velocity hm2_5i25.0.encoder.02.velocity => motion.spindle-speed-in
net spindle-index-enable hm2_5i25.0.encoder.02.index-enable <=> motion.spindle-index-enable

#spindle_orient
net spindle-position-0to1 hm2_5i25.0.encoder.02.position => orient.position => orient-pid.feedback => motion.spindle-revs => near.0.in1
net orient-angle motion.spindle-orient-angle => orient.angle
net orient-enable motion.spindle-orient => mux2.0.sel => or2.0.in1 => and2.0.in1 => orient-pid.enable => orient.enable => and2.1.in0
#####setp timedelay.0.on-delay 2
#####setp timedelay.1.on-delay 1
#######net spindle-in-position near.0.out => timedelay.0.in => timedelay.1.in
#######net spindle-in-position5 timedelay.1.out => and2.1.in1
#######net spindle-in-position8 or2.2.out => parport.0.pin-02-out
net spindle-in-position10 or2.2.out => parport.0.pin-02-out
net spindle-in-position9 and2.1.out => or2.2.in1
net spindle-in-position8 or2.2.in0 <= motion.spindle-locked
net spindle-in-position7 parport.0.pin-13-in => or2.1.in0
#####net spindle-in-position2 timedelay.0.out => and2.0.in0
#####net spindle-in-position2 timedelay.0.out => or2.1.in1
net spindle-in-position3 or2.1.out => and2.0.in0
net spindle-in-position4 and2.0.out => motion.spindle-is-oriented
setp orient-pid.maxoutput 0.25
setp orient-pid.Pgain     10                                           # 4.1
setp orient-pid.Igain      0
setp orient-pid.Dgain      0
setp orient-pid.FF1        0.0013
setp orient-pid.FF2        0.0002
setp orient-pid.deadband   0.001

setp near.0.difference 0.01 # (3.6 degrees)

############# End Spindle Encoder #############

#and then connect the encoder to the 7I76's encoder input

net spindle-vel-cmd-rps        <= motion.spindle-speed-out-rps
net spindle-vel-cmd-rps-abs    <= motion.spindle-speed-out-rps-abs
net spindle-vel-cmd-rpm        <= motion.spindle-speed-out
net spindle-vel-cmd-rpm-abs    <= motion.spindle-speed-out-abs
net spindle-enable                 motion.spindle-on => or2.0.in0 ######*#
net spindle-cw                 <= motion.spindle-forward #temp test orientate
net spindle-ccw                <= motion.spindle-reverse
net spindle-brake              <= motion.spindle-brake
net spindle-at-speed           => motion.spindle-at-speed

#These lines in hal gave sensible readings on the halscope. Note the scale now the same as scale in the ini file.
#These settings get pwm on gpio008 working
setp hm2_5i25.0.pwmgen.00.output-type 1
setp hm2_5i25.0.pwmgen.00.scale 36
setp hm2_5i25.0.pwmgen.pdm_frequency 5000000
setp hm2_5i25.0.pwmgen.pwm_frequency 5000
net spindle-vel-cmd-rps => mux2.0.in0
net selected-spindle-vel-cmd-rps mux2.0.out => hm2_5i25.0.pwmgen.00.value

#change num_pwmgens=0 to num_pwmgens=1(note this cannot be selected in Pncconfig 5i25/7i76)
setp hm2_5i25.0.gpio.025.invert_output true
#net spindle-enable => hm2_5i25.0.pwmgen.00.enable #comment out for orient mod
net spindle-enable => or2.0.in0
net selected-spindle-enable or2.0.out => hm2_5i25.0.pwmgen.00.enable ######*#=> hm2_5i25.0.gpio.017.out

Endocder - hostmot2

Pins:

    (s32 out) count
            Number of encoder counts - up and down - since the previous reset.

    (float out) position
            Encoder position in position units (count / scale).

    (float out) velocity
            Estimated encoder velocity in position units per second.

    (float out) velocity-rpm
            Estimated encoder velocity in position units per minute.

    (bit in) reset
            When this pin is TRUE, the count and position pins are set to 0. (The value of the velocity pin is not affected by this.) The driver does not reset this pin to
            FALSE after resetting the count to 0, that is the user's job.

    (bit in/out) index-enable
            When this pin is set to True, the count (and therefore also position) are reset to zero on the next Index (Phase-Z) pulse. At the same time, index-enable is re‐
            set to zero to indicate that the pulse has occurred. (Is This is an edge triggered event? ) The motion component sets spindle.S.index-enable (in/out) to TRUE at the beginning of a spindle-synchronized move (Thus zeroing the spindle count - at the start of the spindle-synchronized move. )

    (s32 out) rawcounts
            Total number of encoder counts since the start, not adjusted for index or reset.

    (bit out) input-a, input-b, input-index
            Real time filtered values of A,B,Index encoder signals

    (bit in) quad-error-enable
            When this pin is true quadrature error reporting is enabled. when false, existing quadrature errors are cleared and error reporting is disabled

    (bit out) quad-error
            This bit indicates that a quadrature sequence error has been detected. It can only be set if the corresponding quad-error-enable bit is true

    (u32 in) hm2_XXXX.N.encoder.sample-frequency
            This is the sample frequency that determines all standard encoder channels digital filter time constant (see filter parameter)

    (u32 in) hm2_XXXX.N.encoder.muxed-sample-frequency
            This is the sample frequency that determines all muxed encoder channels digital filter time constant (see filter parameter) This also sets the encoder multiplex‐
            ing frequency

    (float in) hm2_XXXX.N.encoder.muxed-skew
            This sets the muxed encoder sample time delay (in ns) from the multiplex signal. Setting this properly can increase the usable multiplex frequency and compen‐
            sate for cable delays (suggested value is 3* cable length in feet +20)

    (bit in) hm2_XXXX.N.encoder.hires-timestamp
            When this pin is true the encoder timestamp counter frequency is ~10 MHz when false the timestamp counter frequency is ~2 MHz. This should be set true for fre‐
            quency counting applications to improve the resolution. It should be set false when servo thread periods longer than 1 ms are used.

            Parameters:

    (float r/w) scale
            Converts from 'count' units to 'position' units.

    (bit r/w) index-invert
            If set to True, the rising edge of the Index input pin triggers the Index event (if index-enable is True). If set to False, the falling edge triggers.

    (bit r/w) index-mask
            If set to True, the Index input pin only has an effect if the Index-Mask input pin is True (or False, depending on the index-mask-invert pin below).

    (bit r/w) index-mask-invert
            If set to True, Index-Mask must be False for Index to have an effect. If set to False, the Index-Mask pin must be True.

    (bit r/w) counter-mode
            Set to False (the default) for Quadrature. Set to True for Step/Dir (in which case Step is on the A pin and Dir is on the B pin).

    (bit r/w) filter
            If set to True (the default), the quadrature counter needs 15 sample clocks to register a change on any of the three input lines (any pulse shorter than this is
            rejected as noise). If set to False, the quadrature counter needs only 3 clocks to register a change. The default encoder sample clock runs at approximately 25
            to 33 MHz but can be changed globally with the sample-frequency or muxed-sample-frequency pin

    (float r/w) vel-timeout
            When the encoder is moving slower than one pulse for each time that the driver reads the count from the FPGA (in the hm2_read() function), the velocity is harder to estimate. The driver can wait several iterations for the next pulse to arrive, all the while reporting the upper bound of the encoder velocity, which can be accurately guessed. This parameter specifies how long to wait for the next pulse, before reporting the encoder stopped. This parameter is in seconds.

    (s32 r/w) hm2_XXXX.N.encoder.timer-number (default: -1)
            Sets the hm2dpll timer instance to be used to latch encoder counts. A setting of -1 does not latch encoder counts. A setting of 0 latches at the same time as
            the main hostmot2 read. A setting of 1..4 uses a time offset from the main hostmot2 read according to the dpll's timer-us setting.

            Typically, timer-us should be a negative number with a magnitude larger than the largest latency (e.g., -100 for a system with mediocre latency, -50 for a system
            with good latency).

            If no DPLL module is present in the FPGA firmware, or if the encoder module does not support DPLL, then this pin is not created.

            When available, this feature should typically be enabled. Doing so generally reduces following errors.

tmp

Servo-loop link https://forum.linuxcnc.org/24-hal-components/38141-closing-the-servo-loop-with-hal-mesa-7i76

Building LinuxCNC

https://gnipsel.com/linuxcnc/uspace/debian9-eth.html

GUI Frontends
axis - solid
Gscreen (uses gladeVCP) PathPilot??
TkLinuxCNC GUI

hazzy new

Display screens - GUI

Qtvcp is an infrastructure to display a custom CNC screen or control panel in LinuxCNC. It displays a UI file built with the QTDesigner screen
Gmoccapy

nativeCAM seems like a key feature.

Axis

As of 2.8 put a file in ~/linuxcnc/misc/axicrc to fix up things.
Default screensize:

 max size root_window.tk.call("wm","geometry",".","1900x1200")
# or - To have Axis open up at the maximum size for
your screen use:

#maxgeo=root_window.tk.call("wm","maxsize",".")
#fullsize=maxgeo.split(' ')[0] + 'x' + maxgeo.split(' ')[1]
#root_window.tk.call("wm","geometry",".",fullsize) #for now
root_window.tk.call("wm","geometry",".","1600x1000")

Modes of Operations

Manual - items under manual control tab should work
MDI(Manual Data Input)

Gmoccapy

Andy uses Gmoccapy with nativeCAM

gladevcp - added to other bits

gladevcp gives a fairly useable interface to create GUIs..

To test -

 gladevcp_demo -H custom.hal gvcp-panel.ui

During test - run

halcmd show all

This gets you the pin names.. you can also run halmeter. The names are not consistent - gvcp-panel.motor_current gets set as gladevcp.motor_current in custom_gvcp.hal

The ini file tells gvcp where to look for the python handlers.py file in this line: GLADEVCP= -u handlers.py -H gvcp_call_list.hal gvcp-panel.ui

Homing settings

ini

[TRAJ]
NO_FORCE_HOMING =
HOME =
POSITION_FILE =

[JOINT]
HOME =
HOME_OFFSET =

Gcode generators

https://github.com/linuxcnc/simple-gcode-generators

General CNC notes

https://www.warrensbrain.com/gcode-to-english-translator.html

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