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NB70
19-07-2021, 02:06 PM
I've got a Huanyang VFD & 2.2Kw spindle - controlled via RS485 in Linuxcnc using hy_vfd (http://linuxcnc.org/docs/html/man/man1/hy_vfd.1.html). Twice in the recent hot weather the VFD has displayed the E.O.H.n error - which is overheating of the VFD. This shut down the spindle but the machine carried on with the cutting move which would have been damaging if I hadn't been there to pause the program.

Obviously I need to improve ventilation/cooling for the VFD but I also want to make sure that any VFD error will stop the machine cutting.
How do others handle errors from the VFD?


I could explore whether the RS485 connection picks up on errors and stop the machine via Linuxcnc,
I also have a Mesa 5i25/7i76 card which could read an error signal via the VFD mutli-outputs (FA/FB/FC?) and feed that back to Linuxcnc,
or I could bypass the software altogether & connect the VFD multi-output to my safety relay (Pilz PNOZ11) and force an E-stop.


To test out any of the above I would also need to make the VFD display an error condition - does anyone know how to do this?
Many thanks,
Nathan

dazp1976
19-07-2021, 02:41 PM
First have a look at peramiter options in the manual.
Looking at another drive, I spotted that the next perameter after the baud rate value was for communication bits.
It stated that 0 was for no error checking and 1 was for stop bit.

Have a read through and see if you get a lightbulb moment.
I admit I know nothing of vfd's.

On another note.
I came across a plugin / driver that said it was needed for Mach3 for HY vfd's to make it modbus compliant. Could this be a possible scenario with linux?.

JAZZCNC
19-07-2021, 04:52 PM
The VFD as programable Relay Outputs FA, FB, FC which you can tie into your e-stop system, I haven't got a manual to hand but I think it's parameter PD52, with this you can set to the relay to fire when an error occurs.

Doddy
19-07-2021, 07:20 PM
It stated that 0 was for no error checking and 1 was for stop bit.


Just to discount this - this is part of the serial protocol used to communicate with the VFD and is used for the framing of the individual packets of data. Not to be confused with the VFD operation.

Basically, it helps the comms between the computer and the VFD, nothing else.

dazp1976
19-07-2021, 09:56 PM
Just to discount this - this is part of the serial protocol used to communicate with the VFD and is used for the framing of the individual packets of data. Not to be confused with the VFD operation.

Basically, it helps the comms between the computer and the VFD, nothing else.

Ok.
So it's the normal I/O outputs to relays / contactors and estop circuits doing the work then.
Good to know.

NB70
20-07-2021, 10:09 AM
Many thanks for the help. I've checked the manual & you're right its parameter PD052, it needs to be set to 3 for fault indication.
I want to be able to use the machine sometimes with the VFD turned off (for probing etc.).


If the VFD's normally closed outputs (FA/FB) are still closed when the VFD is off I can connect these directly to my PNOZ safety relay. I should be able to check this with a multimeter.
Otherwise my plan is to connect FB & FC to a separate relay (something like this (https://uk.rs-online.com/web/p/non-latching-relays/8886798/)?) and then connect that into the E-stop circuit from the PNOZ relay. Hopefully when the VFD faults, FB + FC switch on which opens the relay and triggers the E-stop.

JAZZCNC
20-07-2021, 07:34 PM
Many thanks for the help. I've checked the manual & you're right its parameter PD052, it needs to be set to 3 for fault indication.
I want to be able to use the machine sometimes with the VFD turned off (for probing etc.).


If the VFD's normally closed outputs (FA/FB) are still closed when the VFD is off I can connect these directly to my PNOZ safety relay. I should be able to check this with a multimeter.
Otherwise my plan is to connect FB & FC to a separate relay (something like this (https://uk.rs-online.com/web/p/non-latching-relays/8886798/)?) and then connect that into the E-stop circuit from the PNOZ relay. Hopefully when the VFD faults, FB + FC switch on which opens the relay and triggers the E-stop.


Yes the NC contact is still closed when off, BUT, why would you turn the VFD off for probing.? If you are chasing safety then just put an interlock switch on the run wire.!