[fgant34]

I have a Windows 10, Dell Optiplex 9020. While cutting I keep getting the Controller Disconnected Error. SW: 2020.03.14. HW: 2020.03.12.

Device listed in windows is: CNC USB Controller Mk3 v2. Which is what I have. Driver date is 9-22-2016 ver. 1.0.0.1

I have replaced the USB cable with no change. I have tried every USB port on the front an back of the PC, there are 10. I have routed the usb cable away from all other wiring. No change. Yesterday I cut all day and it happened 3 times. Today it has happened so often I've given up cutting.

I could use some guidance. Thanks

[Teketeke]

https://www.cnczone.com/forums/plane...98896-cnc.html

[fgant34]

https://www.cnczone.com/forums/plane...98896-cnc.html

I saw that thread. The thing is, it worked before v2.

[maki]

post #3 solve my problem

[fgant34]

Moving my ground fixed my issue.

[basilevscom]

Hello!
I have two CNC machines with USB controllers Mk3/4 (3 axis)
All equipment is the same-computers, drivers, motors, wires, power supplies...
USB wire shielded with two ferrite filters 1.2 meters long.

The first machine works well, but can sometimes stop 2-3 times a day in the middle of the program.
There are no error messages, the spindle is switched off, cooling is still enabled.
I can continue working from any line of code.

The second machine always performs the "HOME" procedure and you can manually burn the axes.
But it always stops with the message "Controller Disconnected" when performing the first G1 movement in the program.
At the same time, this situation does not envy the operation of power supplies drivers, motors, spindles and other power devices - the problem is only in the connection between the computer and the controller.
I completely rule out problems with noise and power leads or a problem with jamming.
USB works well with the scanner and printer, intervuys USB is sure to work with all devices.
Do you have any ideas other than replacing the computer and cable?

Thanks!

[PlanetCNC]

This is noise/power/ground issue for sure. You can not rule this out.

[basilevscom]

Are you talking about the first machine or the second?
I can rule it out (noise/power/ground issue) for second machine.
After HOME procedure I turn off ALL power except the computer and controller and always have an error when I first command G1

I think this is due to active data transfer to the controller`s buffer. Is there any way to test this?

[PlanetCNC]

How are your limit switches connected?

[basilevscom]

All limit sensors are connected via optical decoupling chips according to the recommendations on the site:
https://planet-cnc.com/how-to-connec...-limit-switch/

[basilevscom]

I replaced the computer. The situation has not changed, there is always a connection loss when running G1
I replaced the cable. The situation has changed, sometimes (2-3 times a day) I have a loss of connection with the controller.

I think the problem is with the controller's power supply!
I have a questions for the controller manufacturer - how is the controller's power supply organized?
Why does it work if the external power is turned off?
Does it get power via USB? How can I turn off power via USB?

[blowlamp]

I replaced the computer. The situation has not changed, there is always a connection loss when running G1
I replaced the cable. The situation has changed, sometimes (2-3 times a day) I have a loss of connection with the controller.

I think the problem is with the controller's power supply!
I have a questions for the controller manufacturer - how is the controller's power supply organized?
Why does it work if the external power is turned off?
Does it get power via USB? How can I turn off power via USB?

If this problem were mine, I would disconnect everything except the USB connection and run some gcode to try and isolate the fault.
Then reconnect things one at a time until the fault comes back.

[basilevscom]

My experience in electronics development tells me that if the operation of a device depends on the quality of the cable it is a bad device (((
The sad thing is that I wanted to buy two more controllers, but if it's so unstable...

(I have 2 more machines running on LinuxCNC via LPT port for more than two years without any failure.
If I don't find a real solution when the work doesn't depend on the quality of the cable and computer, I will have to throw out these controllers and look for other hardware.)

[maki]

I have (occasional) the exact same problem with foam cutting interface (GGC2) equiped with atmega chip on it. Maybe something that related...

[PlanetCNC]

Electrical interference causes errors in USB transmissions. USB uses differential signals which are more resistant to noise but main problem is power. USB is not galvanically isolated like Ethernet. Grounding is major issue.

CNC controller is very intense USB device. This means a lot of big packets at high speed.
USB has built-in error detection. But in bad conditions many errors get through anyway. Controller detects this and asks for retry. You can monitor this statistics in log.


Like I said, USB also have built-in error detection. If there are a lot of these errors then computer disconnects USB device because it assumes device is faulty. This is when "disconnect" happens.
Using active USB cable (or USB hub) often helps because it filters out all those bad packets and they never reach computer.

But filtering out noise generators and fixing ground issues is correct way to address this issue. There is no recipe for success. When done correctly USB works reliably even in high noise environments.

[basilevscom]

Thanks for the answer! (I'm an electronics developer I understand everything about data transfer speed and grounding)

How do you explain the presence of this error if controller have not galvanically connected to circuits with noise?
Please explain me about the power supply of the controller - is the DSP processor powered via USB or from an external power source?
What is the current consumption of the controller? This is very important!
My controller works even when I don't turn on external power, is this normal?

[PlanetCNC]

Controller must be powered with external power supply. 12V, at least 600mA is recommended. Actual consumption depends on what is connected.
Without external power, controller will turn on but because of voltage drop USB connection will not work reliably.

[basilevscom]

I use 12V 1.5A power supply for controller, LPH-18-12 Mean Well.
But if the controller can work both power ways, how do I determine if the external power supply is working normally?
The power led will light up in both cases...

If the external power supply of the controller is connected (+12V), the current via the USB cable (+5V) must be zero?
Can I disconnect pin 1 in cable connector (USB Power +5V)?

[basilevscom]

Controller must be powered with external power supply. 12V, at least 600mA is recommended. Actual consumption depends on what is connected.
Without external power, controller will turn on but because of voltage drop USB connection will not work reliably.

Maybe I need to start with replacing the power supply and not with replacing the cable or computer?

[PlanetCNC]

USB cable without 5V can damage controller is external power is not connected.
You can measure voltage on one of 5V pins if you have 5V then power supply is good. At least in electrical way, grounding can still cause issues.

You mentioned you use shielded cables. How and where are shields connected?