Centroid Community CNC Support Forum

ashesman wrote: ↑Mon May 06, 2024 6:49 pm Chapter 14 of the manual lists a lot of causes for over volt and over current faults during deceleration. Have you reviewed them?

05-05 is a base motor parameter. It tells the VFD how much current the motor draws when unloaded. It should be set by auto tuning. Or manually by running the motor with no load and watching the current.

No load current is used by the slip compensation algorithm to know when it should do slip compensation or not.

I suspect that changing 05-05 has probably masked the problem rather than fixed it.

There is mention in the faults section of the manual of the stall prevention setting being lower than no load current causing faults.

Setting the base motor parameters correctly and then adjusting the other features to suit would be best.

cncsnw wrote: ↑Sat Jul 13, 2024 8:19 pm Yes, you can connect a probe via the MI8 interface to the Centroid control.

If you want to use the "PROBE" header on the Oak, then you would wire the B6 and B7 terminals to pins 3 and 8 of the Oak PROBE header.

If you want to use ordinary PLC inputs (e.g. any of INP13-INP16 on the Oak) then you would wire the B6 and B7 terminals to the Oak input, and to your inputs common voltage (e.g. 0VDC, if you have +24V wired to the bank common.

In either case, you will need to wire a 24VDC supply directly from your distribution terminals to MI8 terminals A5 and A6. There is no 24V supply pin on the Oak PROBE header; only 12V, which is not sufficient for the MI8.

I do not immediately see a way to automatically detect whether the probe is connected or not, separate from the N.C. trip signal.

For best protection against operator error, you want a separate normally-open input signal, wired to another input, which closes when the probe is connected. If you have such an input signal, and you set the input number in Parameter 18, then CNC12 will prevent you from trying to run a probing cycle without first connecting the probe; and your PLC program will prevent you from starting the spindle with the probe connected.

Also, if your probe-trip input is going to indicate a trip state when the probe is disconnected, then you need to either provide a probe-detect signal and set Parameter 18; or you need to leave the probe connected at all times.

If there is no way, through the MI8 interface or the probe itself, to automatically detect whether the probe is connected; but you still want the benefits of a probe-detect signal, then you can build a probe storage cradle with a normally-closed limit switch in it, so that the switch is tripped (open) when the probe is placed in storage. The control can then assume that if the probe is not in its storage cradle, then it is in the spindle.

cncsnw wrote: ↑Sun Jul 14, 2024 2:33 pm For the probe-detect signal, connect pin 2 or 3 (the 12V COM) to pin 9 (INP771) of the Oak PROBE header.

With the probe-trip signal on pin 8 (INP769) and the probe-detect signal on pin 9 (INP771), you would set:
- Parameter 11 = 50769
- Parameter 18 = 50771
Those are the default values for those parameters.

If your probe-trip signal is normally-closed (closed/green when not tripped; open/red when tripped) then make Parameter 11 negative. I.e. set it to -50769 instead of +50769.