Oak with Delta C2000

[cncsnw]

Swapping the A channel with the B channel will not, by itself, introduce any signal errors.

It will just make the encoder count in the opposite direction, which just means you change the sign of the value you put in Parameter 34.

If the displayed spindle RPM goes to zero, then you are not receiving any counts on the A channel; the B channel; or both.

Check the PID Encoder information screen (F1/Setup -> F3/Config -> "137" -> F4/PID -> F3/Encoder) to see if it is showing differential or quadrature errors on the spindle encoder input (axis #6). Also watch that display as the spindle runs, to see if feedback periodically stops.

[harishom]

Today I checked connections again. and Tried parameter 78 to 0 .The result is same. any help will be appreciated here. kinda lost.

[harishom]

Ok so programmed RPM = 500 -->0 --> -500 spindle rotates correctly in both directions. 500 >0-> -500 ->0 == 1 tapped hole . it taps couple of holes and stops after COMPLETING cycle and moving to next hole, when i get "Waiting for spindle direction" at that time spindle speed is 0 . really confused whats going on here.

[cncsnw]

it taps couple of holes and stops after COMPLETING cycle and moving to next hole, when i get "Waiting for spindle direction" at that time spindle speed is 0

But at that time, when it is at the next hole, not moving the Z axis, and the message window says "Waiting for spindle direction":
- The displayed spindle speed in the status window is 0?
- You changed P78 back to 1, so that the displayed spindle speed is the encoder speed?
- Or did you leave P78 set to 0, so that the displayed speed is the PLC's intended speed?
- The spindle is, in fact, turning at ca. 500 RPM?
- The spindle is, in fact, turning forward (having switched from reverse to forward after finishing the previous hole)?
- You are using G84 for right-hand threads?

Assuming that P78 = 1, and the spindle is turning forward at ca. 500RPM, and the RPM display in the status window says 0, then this still looks like a signal problem. Do you have an oscilloscope you can use to monitor the A and B channels going into the Oak DE9 connector?

[harishom]

here are the answers.

- The displayed spindle speed in the status window is 0? yes spindle stops randomly after completing 1 cycle and aligned to next hole.
- You changed P78 back to 1, so that the displayed spindle speed is the encoder speed? yes back to 1
- Or did you leave P78 set to 0, so that the displayed speed is the PLC's intended speed?
- The spindle is, in fact, turning at ca. 500 RPM? spindle always shows right RPM +500 and -500 for reverse
- The spindle is, in fact, turning forward (having switched from reverse to forward after finishing the previous hole)? as soon as xyz are aligned to next hole it says "waiting for spindle direction". and spindle is not at all moving at that point .
- You are using G84 for right-hand threads? yes G84 right hand threads

Don't have oscilloscope
Completely lost now.

[cncsnw]

Based on your response, I still cannot tell whether the spindle is turning, or stopped, when the problem occurs.

The spindle is, in fact, turning at ca. 500 RPM? spindle always shows right RPM +500 and -500 for reverse

Where does it show this? That sounds kind of like you are describing the spindle RPM display in the CNC12 status window on the computer screen; but I thought you said that display ready zero when the problem happened.

it says "waiting for spindle direction". and spindle is not at all moving at that point .

Does "not at all moving" mean that it has stopped turning?

[harishom]

ok let me describe in detail.
So there 10 holes to be tapped M6 on a plate.
After pressing cycle start , normal tapping process starts . I see correct programmed rpm on console.
Tapping completes for couple of holes and then when message displays "waiting for spindle direction" and xy aligned to next hole to be tapped. spindle just not starts the tapping cycle. it waits forever there.

May be this is more elaborate description.
I will try to make video if its needed.

[harishom]

Added video , since file is large adding link to youtube video here

https://www.youtube.com/shorts/BNWLigarhyY

Please review.
Appreciate all the help so far.

Thanks

[cncsnw]

Okay, I think you have made it clear that the spindle does not restart, in the forward direction, after it finishes tapping the preceding hole.

I assume, in the video you just posted, that you had changed Parameter 78 back to 0. Please leave Parameter 78 set to 1.

The spindle speed display in the status window says 0 because the spindle speed is 0.
The tapping cycle says "waiting for spindle direction" because it cannot proceed until it sees -- by the spindle encoder counts -- that the spindle has resumed running forward.

Now the question is, why is the spindle not restarting and running forward?
- Did the PLC not turn on OUT7, to tell the VFD to run?
- Did the PLC turn on OUT7, but fail to provide a non-zero analog speed command to tell the VFD how fast to run?
- Did the PLC provide both those things, but the VFD failed to act upon them?

You can press Alt-i while the job is running -- e.g. while it is in a tapping cycle, with the "waiting..." message -- to show the PLC Diagnostic display. On the PLC diagnostic display, you can see whether OUT7 is red (off) or green (on). OUT7 is the 7th dot on the 2nd line.

You can probably also learn something from the LED indicators on the C2000 keypad. Watch the LED indicators while the spindle is running normally in each direction, and while it is stopped normally. Compare that with what you see when the spindle should be running (for a tapping cycle) but is not.

[harishom]

Thanks cncsnw. I Will give it a shot tomorrow and post the outcome.