Advanced Search

What model of servo motor are you using?

I actually only tested that "tee" line.
But now I have tested the script and it fails on the "apt update" line.


Found it, there should be a "-P" in the wget command
The output of "apt list --upgradable" shows a number of 2.10 packages such as
linuxcnc-uspace/stable 1:2.10.0~pre0.4165.g55fb1a0267 amd64

I'm on the stable version

Gents,

Continuing my learning process of LinuxCNC and Mesa cards i've managed (thank you PCW and tommylight!), to start my permanent magnet DC servomotor driven by BTS7960 H-bridges, all hooked up to Mesa 7i95T on the test bench.
forum.linuxcnc.org/configuration-tools/5...-bridges-pmdc-servos

Did some basic PID tuning and motors are not reaching following errors. Ferror is loose however - fine tuning not required at this stage.
On my learning short list now there is two topics:
1) encoder-ratio module
2) Mesa THCAD card. As I'm powering my motors and limit/home switches from old laptop power supply - its voltage sags easily when loading servos so found it good opportunity to practice THCAD and PyVCP by reading power supply voltage and present it on AXIS. 

Ad 1) While reading LinuxCNC documentation i found an interesting function ENCODER_RATIO. First thought was "hey! let's do some experiment and slave Z axis servo to X.". Let's say the final idea is to link spindle encoder with rotary/dividing head servo - i can imaging hobbing gears like that:)
Experiment conditions:
- there is three servos available X, Y, Z so three encoders, all the same ppr = 400
- X will be the master, Z will be slave
- i want Z to turn 4 times slower than X

If i understand the documentation right i did the following:
- detached joint.2.motor-pos-cmd from pid.z.command
- detached hm2_7i95.0.encoder.02.position from pid.z.feedback and joint.2.motor-pos-fb
- connected pid.z.feedback and joint.2.motor-pos-fb with encoder-ratio.0.error
- decided to use one of the switches for slave axis on/off so detached remote e-stop (will not using it now) input hm2_7i95.0.inmux.00.input-06-not and hooked it up to encoder-ratio.0.enable
- connected master axis (X) encoder signals A and B to encoder-ratio.0.master-A and encoder-ratio.0.master-B
- connected slave axis (Z) encoder signals A and B to encoder-ratio.0.slave-A and encoder-ratio.0.slave-B
- set ratio by stating ppr: encoder-ratio.0.master-ppr 400 and encoder-ratio.0.slave-ppr 100

AXIS started with no issues. Checked HAL configuration and what i can see is:
- encoder-ratio.0.master-A and B signals are successfully connected to X encoder
- encoder-ratio.0.enable is ok - turning TRUE when switch is activated by me

And i failed successfully:)
- i can see no change on pid.z.feedback as well as on pid.z.output when i move X axis - no change on encoder-ratio.0.error 

I thing i'm not getting fully what manula says about encoder_ratio. i couldn't find any HAL examples showing correct configuration.
What i found is that unfortunatelly encoder-ratio.0.master-ppr and encoder-ratio.0.slave-ppr are PARAMETERS, not PINS so no chance to make nice 'change ratio' option in PyVCP (imagine you can input different spindle/slave axis ratio and hob whatever spur gear you want!). The only option i see it close LinuxCNC, edit ppr numbers and re-start LinuxCNC to get ratio i want.

My idea was to have motorized dividing head connected and with just one switch make it move in sync with spindle @ required ratio...So it is basically ELS. Ehmmm those dreams.

Anyway, please! Could you guys look at it and poke me in good direction? I did research and tried by myself before i bother you but, as i said before, failed successfully:)
Thank you.

hi, thanks!
Is there any code or links to refer to?

hi，here's another question. I want to read from and write to the module (for example the shared memory module in realtime space) through pins in user space.How can I solve the problem? Is there any code about this?

sadly so yes, although i cannot help but think there must be a simpler way to do this with mux, just somehow switch between position and velocity modes depending on an input

its fairly complex...

You might take a look at this, using the orient component.

forum.linuxcnc.org/10-advanced-configura...is-from-inside-gcode


 

I'll have this information for you tomorrow.

Thanks for the help.

if you can run

and attach the lspci.txt file (photos are difficult to work with if you want a proper answer) and I can give some answers.

Just gone 3pm here in Sydney.

No something interesting.

I worked on a little project using an FPGA dev board to run MESA's hostmot2 firmware. First attempt was based on the 7c81 using either SPI (raspberry pi) or EPP (best on motherboard based parallel ports). The issue with the board I used is that the EEPROM need to be changed and the headers were already soldered on.
That same hardware can also be used with the LinuxcncRIO project.

Another project I had a go at was modding the 7i90 Smart serial firmware to support 4 encoders to run on a dev board.

For my latest I've grabbed a different dev board (eeprom is correct size & bought with the headers unslodered, but this time I'll be trying a Ethernet interface, chip is same as use on the Mesa products, so no having to rewrite a driver, which requires a couple of steps, first being working out the instructions of the softcore, working how the driver talks to the chip and then how it integrates with the rest.

Some pics, 2x17 ports from breakout boards (mesa 25 pin daughter boards can be used as well) and 4 extra pins for 2 smart serial ports or extra I\O.

First off is the FPGA from aliexpress:
 

The Ethernet board, this is experiment only, the FPGA board sits on top, disregard the type of 2x25 headers they can be changed to suit. Should have the boards in a couple of weeks.
 

One of the daughter boards from the orignal project.
 

My worry was that I was missing something that led other (more knowledgeable people) to mark this chipset as not working with LinuxCNC, but as you said if it works, it works.

Hopefully this post helps someone in my same situation in the future.

Thanks a lot for your answer.

forum.linuxcnc.org/10-advanced-configura...to-example-mesa-7i77
The same procedure and tuning is valid for 7i97T.
Especially mind the wiring of e-stop and drive enable, those can not be skipped.
-
First you have to get the drives running correctly, with no Mesa and no LinuxCNC. This i can not help with, the rest is quite easy, just follow the above and post here whenever you bump into something strange.

At a guess
4PM in Australia
12AM or 1AM in Brazil
?
6AM here...

OK.

The Linux Kernel loads drivers based on the PCI ID, there's nothing special about it. If it sees a particular PCI ID it loads the driver that matches.
So the reason lInux will load the parport_serial is because that's what the card is reporting.

For Tommy, I replied with what might be the issue directly under your post. But without the PCI ID, end manufactures can change this usually via an eeprom or maybe some other method, there's not enough info to go on.