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Hello everyone,

I am currently setting up my plasma cutter and encountering some initial issues that need resolution. One of these issues is the intermittent loss of my THC encoder signal, which occurs briefly at irregular intervals. Aside from this, the signal quality appears to be satisfactory in terms of noise. When the signal is lost for a few milliseconds, the torch attempts to compensate by raising itself before leveling again. I have attached a photograph (apologies for the quality) that illustrates the signal drop, followed by a voltage increase caused by the raised torch before it levels again.

I am utilizing a Beckhoff EL5101 incremental encoder interface in conjunction with a Mesa THCAD2. I have also tested with a THCAD300 I had available, and the issue persists. Additionally, I am employing hypersensing with a second THCAD2 and another Beckhoff EL5101, exhibiting the same behavior. Given that I previously used the THCAD300 with a 7i76e without issues, I suspect that the Beckhoff modules might be the cause.

Attached are three screenshots: one showing arc voltage at 0V, another displaying encoder frequency initially at 0V and then at 12V for testing purposes, and finally, the problematic screenshot showing encoder frequency during cutting. What options do I have to filter these signal drops effectively?

Thank you in advance for any advice or recommendations.

Try also
www.mesaus.com
Replacements:
7i76E
7i95T
7i92TM + 7i76
7i92TM + 7i85S

I was able to cause it to crash out without going into Linux CNC if i load it up too much with commands like
sudo chrt 99 ping -i .001

It handled running realtime at 1ms delay with averages of .101ms  for 10000, 20000 and 30000 pings, but when I jumped to 50000 pings it crashed out at about 40k pings..

So there is something that someone in the "chain" doesn't like under high network traffic..

and again, unplugging and plugging back in (just the network) fixes it... which is... wierd... (to me)..

Here is my Servo Period:
SERVO_PERIOD = 1000000

and here is my Servo Timeout
setp hm2_7i76e.0.watchdog.timeout_ns 5000000

the whole config can be found here (its where I wrote it a while ago, but my old pc died so working on getting it up and running on this pi)

github.com/Skyfire-community/SVM2-LinuxCNC

jhandel wrote:

Got a strange one with a Pi5...   Network seems fine when I am just pinging my Mesa card (a 7i76e) but when I run Linux CNC, things kick on but then the network crashes and I get a bazillion (technical term) hm2/hm2_7i76e.0: error queuing read iter=xxxx) and everything turns back off.. 

Once it dies I can't even ping the Mesa card (10.10.10.10) until I unplug and plug back in the ethernet cord... Then its happy as a clam pinging.. but once I start up Linux CNC again same crash right as the UI inits. 

(Linux CNC 2.9.3, PI5 8Gb, NVMe Boot)
 

You may want to start reading from here:
forum.linuxcnc.org/27-driver-boards/4223...read?start=20#207308

Unfortunately I don't have any ethernet hardware to test with (only SPI), I have a 7i92 but that's in the mill enclosure and is a PITA to access. From reports the 6.12 kernel on the most recent RPi images have better latency, but I can't say whether that would solve your issue.

Got a strange one with a Pi5...   Network seems fine when I am just pinging my Mesa card (a 7i76e) but when I run Linux CNC, things kick on but then the network crashes and I get a bazillion (technical term) hm2/hm2_7i76e.0: error queuing read iter=xxxx) and everything turns back off.. 

Once it dies I can't even ping the Mesa card (10.10.10.10) until I unplug and plug back in the ethernet cord... Then its happy as a clam pinging.. but once I start up Linux CNC again same crash right as the UI inits. 

(Linux CNC 2.9.3, PI5 8Gb, NVMe Boot)

I've recently updated from 2.8 to 2.9.2  and I'm having issues with the homing of my dual y axis that uses a single limit switch (i'll be adding a second one for auto squaring in the future). Since migrating the Y axis will go to home and them give a switch triggered while in home state 10 error. I've tried adjusting a number of the homing options but none of them resolve the issue. So I'm wondering if there been any changes since 2.8 that would require this setup to be configured differently.

NOTE: I am using a 7i76E and I've attached my config and hal file for reference.   

That looks correct (and indicates a 7I76+7I78 configuration)

all of my test nets stay low whether or not I apply 5v to the pins. 

That is expected as the input must be >60% of the field voltage to be recognized.

Here is 7i76e firmware for a 7I78 on P1 and 7I85 on P2:

 


 

hi, i am studying Linuxcnc and I need to enable coolant on my lathe with an external switch,

my external switch connected to pin as:

an output coolant pin connected as:

how connect  toogle to run flood?
i find this code but understand how it works in linuxcnc


and I find this lesson but don't understand how edit button code to google switch
all my attempts led to errors,

but this code is work good to spindle


and my copy to coolant show error...



And I have a pneumatic spindle chuck and need connect 3 state toggle to open chuck and close chuck,
to open chuсk I receive input but need run 2 step(enable relay(M64 P0) and disable after 3 second(M65 P0))
to close chuсk I receive input and need run 2 step (enable relay(M64 P1) and disable after 3 second(M65 P1))
Maybe this type of chuck is turned on and off differently?
thank you

Readhmid returns: 


IO Connections for on-card -> 7I76
Pin#                  I/O   Pri. func    Sec. func        Chan     Sec. Pin func   Sec. Pin Dir

TB2-4,5                  0   IOPort       StepGen          0        Dir/Table2      (Out)
TB2-2,3                    1   IOPort       StepGen          0        Step/Table1     (Out)
TB2-10,11                 2   IOPort       StepGen          1        Dir/Table2      (Out)
TB2-8,9                    3   IOPort       StepGen          1        Step/Table1     (Out)
TB2-16,17                4   IOPort       StepGen          2        Dir/Table2      (Out)
TB2-14,15                5   IOPort       StepGen          2        Step/Table1     (Out)
TB2-22,23                6   IOPort       StepGen          3        Dir/Table2      (Out)
TB2-20,21                7   IOPort       StepGen          3        Step/Table1     (Out)
TB3-4,5                    8   IOPort       StepGen          4        Dir/Table2      (Out)
TB3-2,3                    9   IOPort       StepGen          4        Step/Table1     (Out)
Internal-Field-IO      10   IOPort       SSerial          0        TXData0         (Out)
Internal-Field-IO      11   IOPort       SSerial          0        RXData0         (In)
TB3-18,19               12   IOPort       SSerial          0        TXData1         (Out)
TB3-16,17               13   IOPort       SSerial          0        RXData1         (In)
TB3-13,14              14   IOPort       QCount           0        Quad-IDX        (In)
TB3-10,11              15   IOPort       QCount           0        Quad-B          (In)
TB3-7,8                16   IOPort       QCount           0        Quad-A          (In)

IO Connections for P1
DB25 pin#             I/O   Pri. func    Sec. func        Chan     Sec. Pin func   Sec. Pin Dir

 1                      17   IOPort       StepGen         5        Dir/Table2      (Out)
14                     18   IOPort       StepGen         5        Step/Table1     (Out)
 2                      19   IOPort       StepGen         6        Dir/Table2      (Out)
15                     20   IOPort       StepGen         6        Step/Table1     (Out)
 3                      21   IOPort       StepGen         7        Dir/Table2      (Out)
16                     22   IOPort       StepGen         7        Step/Table1     (Out)
 4                      23   IOPort       StepGen         8        Dir/Table2      (Out)
17                     24   IOPort       StepGen         8        Step/Table1     (Out)
 5                      25   IOPort       PWM              0        PWM             (Out)
 6                      26   IOPort       PWM              0        /Enable         (Out)
 7                      27   IOPort       PWM              0        Dir             (Out)
 8                      28   IOPort       SSerial           0        TXData2         (Out)
 9                      29   IOPort       SSerial           0        TXEn2           (Out)
10                     30   IOPort       SSerial           0        RXData2         (In)
11                     31   IOPort       QCount           1        Quad-IDX        (In)
12                     32   IOPort       QCount           1        Quad-B          (In)
13                     33   IOPort       QCount           1        Quad-A          (In)

IO Connections for P2
DB25 pin#             I/O   Pri. func    Sec. func        Chan     Sec. Pin func   Sec. Pin Dir

 1                     34   IOPort       None
14                     35   IOPort       None
 2                     36   IOPort       None
15                     37   IOPort       None
 3                     38   IOPort       None
16                     39   IOPort       None
 4                     40   IOPort       None
17                     41   IOPort       None
 5                     42   IOPort       None
 6                     43   IOPort       None
 7                     44   IOPort       None
 8                     45   IOPort       None
 9                     46   IOPort       None
10                     47   IOPort       None
11                     48   IOPort       None
12                     49   IOPort       None
13                     50   IOPort       None


Then for the pullups I get: 
mesaflash --device ethernet --addr 10.10.10.10  --rpo 0x1005
0001FFFF

mesaflash --device ethernet --addr 10.10.10.10  --rpo 0x1004
0001FFFF
 

Hi All, 

Not a major issue, but my spindle speed is varying significantly under contant load. Sometimes during a cut and sometimes when it's just sitting and spinning up under no load and should be at constant speed. I'm not sure how much it varies because if I try to probe the pin the variance disappears, but audibly it slows down as if I ploughed it into a slightly too heavy cut that wasn't enough to stall the motor but enough to bog it down noticably. 
My VFD (AT4 Aliexpress job) is driving a 3 Phase induction motor, 2.2kW, 2 pole. 

The VFD has a 24v output but takes a 10v analog input, so I've just wired the 24v out to a simple voltage divider resistor pair (<5k total resistance) and I'm using that to feed the high side of the digipot on my 7i76e with 7v or therabouts. I tried using my 24v rail that supplies the limit switch, e-stop etc  originally but the spindle speed was varying a lot (under constant load) so I assumed the VFD reference voltage and 24v rail might be too de-coupled and switched to using the VFD output thinking that would be a more consistent Vref for the VFD, but the spindle speed is still varying a lot.

My .ini file has got the SPINDLE_SCALE set to 8000 (It's an 8k RPM spindle), so I used M3 S8000 and then adjusted the vfd paramaters (P73) to get 60Hz, then checked at M3 S4000 and got roughtly 30Hz showing on the VFD screen so it seems to be working OK at max rpm and  linear to within a few hundred RPM at 50%. 

If I try to probe the voltage on the pin the impedance of the multimeter is enough to pull the VFD back to max RPM as soon as I probe it so I can't tell what the VFD vout or analog signal from the 7i76 is when a dip occurrs. My instinct is that the multimeter has some huge resistance in voltage mode and that a weak pullup / pulldown (1Meg?) would help, but I'm not sure so want to check to see if this is typical behaviour, I'm surprised that it doesn't 'just work'

On a separate (but potentially related?) note, I've got a significant AC voltage leakage to the machine frame ground, I'm not sure if this is the VFD itself or the SMPS which feed 72v to the stepper drivers, I need to do some un-plugging and checking. It's enough that you get a tingle if you touch the frame and you're grounded. I'm getting no DC voltage from machine frame to protective earth in the garage, but 20-60v AC showing on the multimeter. If I use current mode and check leakage current from machine frame to ground it immediately trips the RCD, so >>30mA. Not sure if this is an independant thing or if this leakage could be messing with the analog voltage signals. 

Thoughs? Next steps? Independant things or related? What would you do next....

rodw wrote:

Try a Meanwelll MDR-10-5 (2 amp)
 
 

Hi Rod,

Thank you for the suggestion. I like to use the Meanwell MDR-10-5: au.rs-online.com/web/p/din-rail-power-supplies/7127402

It does not include the DIN Rail, which RS Online Supports say is: DIN Rail: au.rs-online.com/web/p/din-rails/6485722?gb=s

I would like to use the terminal blocks as per your spaceship video:





I sent them these two images stating that I would like to use them with the above power supply and DIN Rail.

But supports said not enough info, and suggested this: au.rs-online.com/web/c/connectors/termin...ds=Phoenix%20Contact

I also inquired about the earth one ( yellow and green ), but supports did not give a link for that.

Would you happen to have any suggestion on this terminal blocks, please?

I will use this power supply only for the Mesa 7i96s, so many of this terminal blocks I should need, please?

( For the stepper motors, I understand that I will have to have a separate power supply. )

How to build a spaceship with a Mesa 7i76e ethernet card - a tutorial for new Linuxcnc users

https://www.youtube.com/watch?v=75tAJ4tdBgs

Than you Rod.

Legend thank you!

I stop poking around for now so and just see what mesaflash reports

A 7I76e +7I78+7i85 does need a custom bit file

For just an added 7I78 on P1, theres:

7i76e_7i76x1_7i78x1D.bit

I can make a bitfile for a 7I76E+7I78+7I85 in the next day or so

Note that if you are running LinuxCNC, and depending on the hal file setup
some I/O pins may have been enabled as outputs so it's not a great idea
to connect them to +5V.

7I76E P1 and P2 pins are pulled up so should read high if unconnected
(and not configured as outputs)

You can check this with mesaflash:

mesaflash --device ethernet --addr [card_ip_address] --rpo 0x1004
(for P1)
mesaflash --device ethernet --addr [card_ip_address] --rpo 0x1008
(for P2)

These should both read 0x001FFFF (17 bits of '1's)
with unconnected P1,P2 connectors

Hi All, 

I'm trying to add a 7i78 and 7i85 card to P1 and P2 of my 7i76e. 
When I plug the 7i78 into P1 and mesaflash --readhmid, the usual 7i76e pins show up "on card" and I also get a list of the 7i78 pins on the "IO Connections for P1" list, an encoder and some stepgens, so that looks positive.

However I connected a bunch of test nets in my hal file, something like this but I'm not by the machine and the SSH isn't connecting now so I can't check: 
net test017 <= hm2_7i76e.0.7i76.0.0.input-17
net test018 <= hm2_7i76e.0.7i76.0.0.input-18
net test019 <= hm2_7i76e.0.7i76.0.0.input-19
net test020 <= hm2_7i76e.0.7i76.0.0.input-20

all of my test nets stay low whether or not I apply 5v to the pins. 
Do I need to change something in the FPGA firmware (bitfile?) to define these pin directions? If so, is this a matter of downloading the Xilinx tool or is there a repo somewhere with combinations of mesa bitfiles in there? I've seen PCW on here post them but I'm not sure if they live somewhere! 
Do the IOPort numbers from --readhmid directly map to the hm2_7i76e.0.7i76.0.0.input-nn pins in the hal or am I missing something here? 


When the 7i85 arrives, I'd like to get it reading a glass scale to close the loop on the axes (I could also test this sooner with the encoder input on the 7i78 if I get the scales mounted before the 7i85 shows up, depends on DHL!) presumably the standard firmware shipped in the 7i85 is set up for the right encoder IO so I only need to set up the hal file plug it into the 7i76e, or will that require an update to the 7i76e bin? 

Finally, once the axis position feedback is working and tuned I'd like to get index homing working from the glass scales on top of my existing home switches. From seeing posts on here It looks like i'll need a new bitfile to enable the home-seeking with a limit switch input and home-latch off an index, but the homing config page seems to say I just need to set HOME_USE_INDEX in the .ini ? 

I tried to install tigervnc and it destroyed my system after logingb in with the correct password it just keeps taking me back to the login.So I reinstalled linuxcnc und updated it.now I can not connect to the mesa Ethernet card 7i76Ei get the following error. 

 

Did I do something wrong during installation?