Greetings,

I am getting an error at random times on my CNC machine. I am running 2 KSteps, and a Konnect board plugged into JP6. Here is the Error:

"COMM ERROR AUX1 E5 (signature not A5)"

Does anyone know what could be causing this? I am really at a loss, my machine will run 10-100 cycles and then fault out. After this happens I have following errors on all my axis. Any suggestions on where to go from here would be very welcome.

Thanks,

Scott

Hi Scott,

Sorry to hear that.  That would indicate a noise error in the Konnect Bit7 Communication. 

E5 = 11100101

A5 = 10100101

How long is the Konnect Cable?  Any noisy wiring near the cable?

There is a known Konnect timing issue that occurs when KFLOP Axis #6 is disabled and set to "No Input".  Is that how your Axis 6 is configured?  If so, set Axis #6 to Encoder Input with Input Channel0=0 to see if it helps.

 

Greetings,

I am getting an error at random times on my CNC machine. I am running 2 KSteps, and a Konnect board plugged into JP6. Here is the Error:

"COMM ERROR AUX1 E5 (signature not A5)"

Does anyone know what could be causing this? I am really at a loss, my machine will run 10-100 cycles and then fault out. After this happens I have following errors on all my axis. Any suggestions on where to go from here would be very welcome.

Thanks,

Scott

Hi Scott,

6 inches doesn't sound too long.

It might help to add a (18AWG or heavier) Ground wire between Konnect and KFLOP.

48V Stepper motor wires switching square waves at ~30 KHz and can be very noisy.

Actually A5 is read from Konnect as a last step and is being received as a E5 (bit 6 wrong).  And that causes an error message and Konnect is no longer serviced.  It isn't clear to me why that would cause following errors unless Konnect drives Amplifier Enables or something critical for the drives.  Re-intializing Konnect should make it functional again.  I can't see why you would need to restart the computer.

I'm not sure how encoder noise could be related, but it is certainly possible.

Regards

TK

 

Tom,

The cable is roughly 6" long. Some of the cables for my stepper motors are close to it, they are just 48V so I didnt think they would cause a problem. I am bundling them up and moving them away to see if it helps.

Let me see if I understand correctly - E5 is sent to the Konnect board and then it returns A5. If they don't match it indicates noise and causes a fault?

Regarding axis 6 - I am currently not using it and it is not configured at all in my INIT program. Should I initialize it as you describe, even though nothing is hooked up to it?

What does the KFLOP do when it gets this error? It seems that I have had to restart the entire computer to clear the fault. Is this normal? After that fault it seems to have following errors on whatever axises are moving. Do you think the following errors are tied to this? 

I am also getting random following errors. I have 4 encoders plugged into JP4 with a custom board that I made (we are testing this for the first time). Could it be possible that we are inducing noise somehow on the encoder board that is transferred up into the Konnect board as well? Maybe one is causing the other, or maybe isolated problems.

Thanks,

Scott

Encoder Board-13734.PNG

Hi Scott,

You might check the voltage levels of the Encoder Signals when connected to KFLOP.  JP4 has 150 termination resistors.  Some encoders may not be able to drive that low of resistance.  The high level should be at least 2.4V to be a valid high.

KFLOP JP5 has 47 ohm series resistors to protect the inputs if driven hard above 3.8V.  However JP5 doesn't have internal termination resistors.

It isn't clear to me how/why the encoder signals would cause following errors.  Normally if some encoder noise is introduced to cause a few extra counts the servo will still be able to drive the following error to zero.  However the physical location will be incorrect.  So the physical positions will gradually "drift".  I suppose if the machine was cutting a part this could cause excessive cutting forces and so forth and result in following errors.  Maybe you could describe in more detail what is happening.

Regards

TK

 

Tom,

I am rearranging my electrical cabinets to try to isolate the encoders from any power sources. 

I wonder if some of my problem with following errors could be that I am using JP4 as my encoder inputs now rather than JP5. I have US digital encoders, so I dont think they drive hard up to 5V. I built the following board to simplify my installation. 

Do you think that adding any in line resistors would do anything to help with following errors? Or maybe a pull down resistor which would tie the input to ground through the resistor? If so would you have a suggestion on what value resistor would be most effective.

Thanks,

Scott