Advanced Search

I've run into an interesting issue with my NVEM and would be keen to get your perspective on this. I've been trying to get serial output from the device on the four pin XH header with no luck. Would be good to see the output here as I build up my config and troubleshoot future issues. It would have helped in the issue I had recently where I was accidentally uploading incorrect config files. 

I've probed the signal coming in TTL (Pin 10, yellow signal on oscilloscope) from the MCU, and also out from the MAX232 after conversion to RS232 (Pin 7, shown as the noisy signal in blue on the scope). 
 

To compare, I built up my own circuit with a known working MAX232 chip with the charge capacitors as recommended in the data sheet. Probing my own chip allows me to measure the signal in and out at both TTL and RS232 levels cleanly on the scope so that tells me it's not my 10X probes loading the signal down. This was my initial theory looking at the long rise times. My own circuit was running at 5V so this could be the difference. 
 

I'm not sure why signal coming out of the chip is so noisy. I can see on the board that the chip is getting 3V3 (Pin 16). The board seems to be missing one of the charge pump capacitors (C4 in the datasheet on V-, pin 6) and I wonder if this is the issue? The V+ and V- (pins 2 and 6) shows 4V across them which tells me it's doing something to multiply the voltage needed for RS232 transmission. 
 

I could desolder the chip and see if it behaves properly with all of the recommended capacitors per the datasheet but at that point I'll probably just bypass it and run TTL out to an FTDI module. I see the NVEM manual says that the XH header has "undefined" behaviour so I was surprised to see the MAX232 chip there if they didn't intend to use it for a documented feature. 

The PCB says it is a V6 dated 2022. Has anyone else experienced this issue? What do you typically see on the TX Line on the XH header?
 

I'm trying to mix pwm servos configuration i managed to work finally with your hobbing Andy. I thought there is two options to add something to AXIS - gladeVCP and pyVCP made panels. When i saw you don't have an XML file in the folder you shared with us i thought it is made with gladeVCP. But the i saw some tutorials on yt and 'they' say that for glade-made-panels there should be panel.glade file along with panel.py (plus panel.pyc created by AXIS once is it first time started).
Here is your files and my assumptions on them:
- hobbing.py  (looks like the panel fils, defining its features, making cals on user inputs, is it a stand alone program or is attached to AXIS?)
- hobbing.ui (looks like the graphical axpect of the panel, using XML formatting - similar to XLM file in pyVCP)
- hobbing_gui.hal (connection file between panel and HAL)
- hobbing.ngc (actual NC file containing hobbing cycle, controlling all the axes involved, speciffic to your setup).

Are those files a separate "hobbing software"? I mean standalone panel using linuxcnc started in the background but not using AXIS? I can see in hybbing.py that you are importing linuxcnc, hal and other mysterious modules and see some linuxcnc.start(), linuxcnc.command() ocmmands inside. This is givimg me the impression is it not connected to AXIS gui but rather standalone "module"/interface.

I can see on wiki, you say "...the only other things needed are a Pyvcp panel with a spinbox in it for tooth count...". But, based on the tutorials i saw, why there is hobbing.ui instead of hobbing.xml?

I'll try some iterations with those files but i need to made more changes to my configuration due to the fact that all the toys i have on my test bench are 7i95t, 3 servos, 3 h-bridges and 7 microswitches, so adding my "inexperience" is giving me a headache. Will turn Z axis into A axis and Y servo will turn into a spindle with encoder so in the end i will have a system with X axis only, spindle with encoder and A-slave-axis.

Hello, I can control my X, Y and Z axes in the Stepconf Wizzard without any problems, but as soon as I start the normal program I can only move the X axis, the Y and Z axes can no longer be controlled. 

Maybe this is helpful:

linuxcnc.org/docs/devel/html/plasma/qtpl...tml#_using_qtplasmac

On to the next issue
During setup of the axis (pncconf) and I test the axis movement, it works perfect.
But from Linuxcnc itself i only get it half distance. HOW?
There is no encoder feedback to the Mesa board as the closed-loop is handled between the drive and motor.
It seems others are having similar issues, but i can't get a clear picture of how they fixed it other than basically running double distance in the wizard to get it to do the correct distance in Linuxcnc. But adding complexity with the speed and acceleration.

lead in and lead out is implemanted, M3/5 on every cut also,
but no nesting

tommylight wrote:

...
It's a fuse and a switch in the same box, the picture shows 2 of them.
 

Thank you tommylight,

I understand now. When I searched for "automatic fuses", I did get correct result, such as this one www.aurinkopaneelikauppa.fi/Automatic-Fu...30V-AC-slow-Type-C-2; but I confused them for circuit breakers.

Best regards,

...behai.

 

cmorley wrote:

It's in a library file. qt_action.py

github.com/LinuxCNC/linuxcnc/blob/2.9/li...cp/qt_action.py#L754
 

In this function where in the GUI can set the parameters
search_vel, probe_vel, max_probe, z_offset, retract_distance, z_safe_travel, rtn_method
?

M3 and plasmac feed rate at the start of every cutAnd M5 at the end of every cut.
Also simple nesting or just ability to change the order of cuts would be nice to have.
And lead in and lead out with the option of no lead out.

rodw wrote:

For a control box, the simplest way is to use a switched, EMI filtered and fused IEC connector
www.amazon.com.au/uxcell%C2%AE-IEC320-Sw...Filter/dp/B01FT0VRTS
You can see one of these used at the bottom right of my photo shared earlier.

But in your case, this won't work if you want to switch the router on and off because the current of the router will be too high for the typically 6 amp AC rating. Plus you would not want the electrically noisy router to be on the same side of the EMI filter as your electronics.

So in your case, I would use a fixed power lead and a cable gland to bring mains into the control box to two household breakers around 10 amp. One of these will protect your router circuit and the other your electronics, On the electronics circuit, immediately after the breaker, fit an EMI filter
www.jaycar.com.au/240v-ac-emi-filter/p/MS4001
Then connect all of your power supplies to the filtered mains power.

Filtering the power is really important to avoid spurious triggering from electrical noise. I learnt the hard way.

The next thing to work out is your estop. That's a bit tricky because you need to disable the router and the stepper motor power supply without using any relays that could fail. The estop needs to drop power to your router power and  stepper mains motion. You could use 2 phases of a 3 phase breaker but technically you would then need  to use a safety relay to be compliant.
Its probably acceptable to disable your stepper drivers using the enable pins on them that are usually left disconnected.


 

Thank you Rod,

I have been thinking about your advice on the router, I am trying something I don't have any practical knowledge of, I will just leave this one out, I will get the other three working, as my knowledge increase, I might rewire it again. This just my hobby project. But I really like learning electronics now, I have always been afraid of it.

You are right, the ENABLE pin on the CLT57T-V41 is left unconnected. During my learning of this driver, I used only the Raspberry Pi 4 and Python to program it, setting ENABLE to high disables the motor.

Best regards,

...behai.
 

it was on a belt drive with an omega style configuration.

Hakan wrote:

Can it also do g-code for plasma cutting?
 

Don't have plasma and can't say what is needed, but if you tell me what is missing I can expand it

Can it also do g-code for plasma cutting?

Okay, I will also make a video about what's happening and post it 

I have see value 1 on much example the xml file and not have problem with this value on debian 10 , lcnc 2.9.0-pre0 and ethercat 1.5.2.

I have test on debian 12, lcnc 2.10.0 and etehrcat 1.6.3 with value 1 and 5 and 1000 , but have error synch 5000 ms foe every drive.

only with -1 the error disappears.

What I don't understand is why on Debian 12, when LCNC starts, the PDO information is written to HAL after a few seconds and in sequence, one Ethercat node at a time from 0 to 5, while with the Debian 10 configuration, the PDOs are immediately read and updated in HAL, as soon as LCNC is running.

another difference between debian 10 and debian 12.
I use PCs with two ethernet ports.
With devian 10, with ip a I have 2 network cards enp1s0 and enp2s0,
while with debian 12 I have three, the two physical network cards and one with written: eoe0s0, which is created when ethercat is running.

Could it be that ethercat 1.6.3 unlike 1.5.2 uses a virtual card that in turn closes on a real one?