Spindle not turning on anymore

I have been using a huanyang vfd 220 on 2,2 Spindle without any issues for a month. I just ran a long gcode program that couldn’t display code due to size, When the program finished, I had to manually stop spindle on the vfd. After rebooting system and vfd the spindle is no longer turning on. Indicator on onefinity says it is timeouted on the connection. On the VFD itself if I hit run it does not turn on the spindle unless im doing it wrong. Anybody seen this issue? I have powered off everything multiple times and scratching my head. I don’t know if it is the breakout board side or the VFD. Any help would be greatly appreciated.

Hey Dale,

a lost serial connection can have some trivial causes. Quoting from existing threads:

In case you cannot find the cause after checking all these, you have two more options:

Run the spindle manually, without CNC Controller ModBus control

You will have to alter the two options for “run/stop” and for “speed control” in the VFD to get back to manual mode. As long as they are set to ModBus control, the “run/stop” and “speed” control on the VFD front panel won’t become functional.


control the “run/stop” and the “speed” of the VFD via the analog spindle control of Onefinity Controller (pin 15 “tool-enable” and pin 17 “PWM”).

Thank you! I have checked connections, and everything seems secure and tight. The VFD will turn the spindle on manually if I change the parameters to 0 from 2. If there a way to test the output at the controller with a multimeter? I do not have an oscilloscope. I figure before I dismount my controller and open up the controller to check internal connections. Also, can it possibly be the VFD still or should I be
looking at the controller and breakout board? I appreciate the feedback.

Hey Dale,

this is difficult to say, it could be any of those.

If I would encounter this, and it’s not an unsufficiently shielded and grounded spindle cable that puts its noise on the serial line, I would look whether the contacts on both sides of DB-25 connection are gold-plated. If they are not, I would apply a little Kontakt 60 on the male side, plug the breakout board adapter in and out a few times, and check for timeout again.

Then I would remove the serial cable, with a multimeter set to ohms check it for continuity of both wires between their ends, then check for short-circuit between the two wires, look at the state of the surface on the contacts (use of wire ferrules is strongly recommended, however not every wire ferrule crimp pliers are able to crimp wire ferrules smaller than of 0,5 mm² wires), and put the cable back into place. You could also replace the cable instead of measuring this.

Then, since I know of issues with the breakout board adapters, I would check if you have this issue (already mentioned above).

You would, as the author suggested, first apply pression on the breakout board adapter in direction to the controller box and observe the whether serial connection still reports timeout (you probably need to have stop/run command and speed control on the VFD back to “ModBus control” in order to make the VFD use the interface, and the correct VFD selected in the Onefinity Controller as “tool type”).

Next, as the author suggested, I would check: Does the timeout disappear after you removed the nuts (A) of the DB-25 Port, as shown in the author’s image, and connected the breakout board adapter without the nuts? This is a test where you don’t open the controller, just remove the two nuts on the outside of the DB-25 socket.

I don’t know how the traffic would show up with a multimeter, you can try and set it to AC and a low voltage. Note that the serial line is a balanced line, the signal is between the two wires. Sorry, I’m not at my lab, otherwise I would check how the traffic shows up with a multimeter. With an oscilloscope or a bus pirate it would be easy to check the signal. Note that RS-485 is bidirectional, so check on VFD’s serial port too.

Anyway next what I would do is open the controller case and check if there is continuity between the solder points of pins 13, 14 on the back of the DB-25 socket (on the AVR board) and the corresponding terminals of the breakout board adapter (while it is in place). Please ensure the Controller is powerless then. I would have a look at how the soldering on the back of the DB-25 connector looks like, if the soldering points have some peculiarities.

Another thing you can do instead is check with another VFD.

I re-terminated all connections with ferrules with no resolve. I put a new VFD in the machine and had immediate connection without any errors. Not sure why the serial would fail on the VFD. Thank you for your support.
Happy New Year.

Hey Dale,

did you use the same model/brand to replace it?

That it simply doesn’t work anymore on some cheap chinese VFDs has been reported from time to time. It is difficult to say what the reason is, whether it is bad solder joints, bad chips, or perhaps neglect of ESD safety when handling the device or the connected cables.

A company that repairs computers once reported that since they made all their workstations ESD-safe, they have 30% fewer hardware failures.

Happy New Year.

I used the same model and brand.

Huanyang VFD, single to 3 Phase, Variable Frequency Drive,2.2kW 3HP 220V input AC 10A for Motor Speed Control, HY Series

As I saw this recommended for talking with the controller.

I wanted the Hitachi Drive WJ200-022LF but, it was a 4–6-month lead time. I guess if this fails I will look to that one.

Do you have any suggestions on a 3hp 220v VFD?

Hey Dale,

I would recommend Omron MX2 (Manual) / Hitachi WJ200 (Manual) which are nearly identical. They are made for the industry and support e.g. Sensorless vector control and Temporary ModBus Override and they have an excellent PDF manual.

Be careful when choosing the model, the WJ200-022LF model is for three-phase input. That’s what we have in Europe here in residential areas, but in North America, where you usually don’t have three-phase electricity but split-phase electricity instead, which means you need devices with one-phase input, you would need to buy the WJ200-022SF model.

Be sure to choose one of two possible corresponding braking resistors and the matching footprint EMC filter with it. See “SECTION 5 – Inverter System Accessories” in the manual.

I own the Omron MX2.