KFLOP disables axis when starting inverter for the spindle

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Photojet
Posts: 11
Joined: Mon Sep 27, 2021 2:06 pm

Re: KFLOP disables axis when starting inverter for the spindle

Post by Photojet » Mon Nov 15, 2021 10:46 am

Dear Tom,
TomKerekes wrote:
Thu Nov 11, 2021 9:38 pm
Good. But that's the sensor. What is the circuitry on that board and what is on your prototype board?
That's the circuit of the limit switch.
The prototype board has only connectors on it so that you can disconnect limit switches and drivers from the KLFOP. It has no other components.
Each connector's signal is soldered to a wire that leads to the respective IO pin on JP7, and the GND and 5V are also connected to JP7.
I ordered the USB isolator you suggested and will see whether it finally works with it although I don't see why you shouldn't have to use something like that!?? I've used several other control boards and none had such issues.
Look forward to get a final solution.
Kind regards,
Martin
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TomKerekes
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Re: KFLOP disables axis when starting inverter for the spindle

Post by TomKerekes » Mon Nov 15, 2021 4:15 pm

Hi Martin,
That's the circuit of the limit switch
That looks reasonable. Although the LED/1K Ohm is driving the photo transistor quite hard at ~4ma. The spec sheet only specifies the output to be below 0.4V @ 0.2ma. So this is 20X over that.

You didn't answer my question about what you meant by unconnected.
I ordered the USB isolator you suggested and will see whether it finally works with it although I don't see why you shouldn't have to use something like that!?? I've used several other control boards and none had such issues.
Yes very strange. Do you have an oscilloscope to check for noise?

Did you ever try the filter capacitors near KFLOP?
Regards,

Tom Kerekes
Dynomotion, Inc.

Photojet
Posts: 11
Joined: Mon Sep 27, 2021 2:06 pm

Re: KFLOP disables axis when starting inverter for the spindle

Post by Photojet » Wed Dec 01, 2021 5:35 pm

Hi Tom,

I installed 6 pcs of 1 nF filter capacitors right next to the KFLOP, replaced all the limit switches with ones from Omron- as per the attached datasheet, on which I connected a 2K resistor between Output and Vcc.
Also bought the USB isolator you suggested but as soon as I connect it to the KFLOP, KmotionCNC crashes and displays" KMotion.dll Timeout waiting on Action to complete" and you have to kill the process. Happens every time.
Removing the isolator, all axis start to work with the inverter on, except when you try and jog toward X home limit switch, which is connected to IO 0 on JP7 of the KFLOP.
Checked all connections and the capacitors for all 6 limit switches and they are identical. No shorts anywhere. When I disconnect the limit switch on IO 0 from the KFLOP, the capacitor stays in place, you can jog toward that limit. Used another sensor, which was working fine on Y, put it on X home but again the axis gets disabled when you jog toward this IO 0 switch. The problem is not the switch, nor the wiring to the KFLOP is checked it many times.
Any idea what to do ?

Kind regards,
Martin

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TomKerekes
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Re: KFLOP disables axis when starting inverter for the spindle

Post by TomKerekes » Thu Dec 02, 2021 4:21 pm

Hi Martin,

I think you get the prize for the most difficulty with limit switches. :)
I installed 6 pcs of 1 nF filter capacitors right next to the KFLOP, replaced all the limit switches with ones from Omron- as per the attached datasheet, on which I connected a 2K resistor between Output and Vcc.
I don't see the data sheet.
Also bought the USB isolator you suggested but as soon as I connect it to the KFLOP, KmotionCNC crashes and displays" KMotion.dll Timeout waiting on Action to complete" and you have to kill the process. Happens every time.
Strange the isolator should be totally transparent to the software. Maybe loosing the Earth ground is causing noise problems elsewhere? That message should occur if some Action is not completing. Which Action is not completing?
Removing the isolator, all axis start to work with the inverter on
That would indicate the capacitors eliminated the noise problem.
except when you try and jog toward X home limit switch, which is connected to IO 0 on JP7 of the KFLOP.
Checked all connections and the capacitors for all 6 limit switches and they are identical. No shorts anywhere. When I disconnect the limit switch on IO 0 from the KFLOP, the capacitor stays in place, you can jog toward that limit. Used another sensor, which was working fine on Y, put it on X home but again the axis gets disabled when you jog toward this IO 0 switch. The problem is not the switch, nor the wiring to the KFLOP is checked it many times.
Since you can jog without the wiring but not with the wiring that pretty much proves there must be some problem in the wiring/circuit/sensor.

Note that it is not valid to remove the wiring from an input and leave it floating even with a capacitor connected. It can still float high or low randomly but just more slowly because of the capacitor. It seems you were lucky it floated to the polarity that allows you to jog,

You should troubleshoot why you can't jog when connected. What state does the Digital IO Screen show IO 0 being in? What state does it need to be in to be able to Jog? What is printed on the Console when you Jog? Does the axis disable? What Voltage is the input pin at relative to KFLOP GND?
Regards,

Tom Kerekes
Dynomotion, Inc.

Photojet
Posts: 11
Joined: Mon Sep 27, 2021 2:06 pm

Re: KFLOP disables axis when starting inverter for the spindle

Post by Photojet » Thu Dec 02, 2021 6:20 pm

Hi Tom,

I'd rather stop getting prizes like these :)

Can't upload the datasheet for the sensor as it's 3.2 MB. It's Omron_EESX3173_EESX4173 and you can see it online.

With the USB isolator connected you can't do anything as when you try and press INIT in the KmotionCNC it crashes and you have to force re-start it.
That's when you get the message "KMotion.dll Timeout waiting on Action to complete"

Checked multiple times the wiring and found NO faults. Also switched the sensor on IO 0 with a perfectly working one from IO 1 and still got the same result, meaning the issue is not the sensor.
Is it possible something to be wrong with IO 0 on the KFLOP?

The sate of all limit switches is identical as they are configured the same way and when the sensor on IO 0 is triggered, the board detects it in the Digital I/O screen. Besides, if the inverter is off, you can jog in each direction and motion stops when the sensor is triggered.

The axis gets disabled when you jog toward IO 0 with the inverter on. As I wrote in the previous message, the input voltage on the limit switches is 3.66 V when they have been triggered. The supplied voltage to the KFLOP is 5.2V.

Kind regards,
Martin

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TomKerekes
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Re: KFLOP disables axis when starting inverter for the spindle

Post by TomKerekes » Thu Dec 02, 2021 7:17 pm

Hi Martin,

That would indicate that input 0 still has noise introduced by the inverter whereas the other inputs no longer do. Are you sure the filter capacitor was added correctly in the same manner as the other inputs?

Its very unlikely there is a problem with KFLOP IO 0 as it still works with the inverter off and indicates properly on the Digital IO screen.
Regards,

Tom Kerekes
Dynomotion, Inc.

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