View Full Version : Help needed to connect my VFD to the AXBB controller

14-09-2019, 09:59 AM
Me again! :indecisiveness:

I'm hoping one of you fine chaps can help me, I have set my VFD up manually and tested the spindle to make sure it works as expected but I now want to connect it up to the AXBB for speed and on off control and maybe forward/ reverse although I'm not sure how useful the reverse would be?
I have moved the jumper on the VFD and set the PD00.. values for external control as shown in the manual but the wiring has me confused. I have also removed the jumper on the AXBB to allow 0-10v control.

In the AXBB manual it shows the following
and the VFD has the following

I have no idea what to connect and I dont want to screw up the AXBB after my last experience with the Charge pump output!

Will i need to connect a relay for switching or any kind of protection between the AXBB and VFD?

All help greatly appreciated :indecisiveness:

14-09-2019, 10:38 AM
Connect the VFD ACM (analogue ground) to your 0V/GND level, and the AXBB analogue AO1 output to VI input to the VFD. That gives you your 0-10V control.

Now, I expect O2 and O3 outputs are designated forward/reverse, so connect these to the FOR and REV inputs to the VFD. As these are digital inputs to the VFD you'd best connect the DCM (digital ground) to your 0V/GND as well.

You say you've set PD00... : so I guess you've unlocked PD000, PD001 = run control = external = 1?, PD002 = operating freq = external = 1, PD044 = FOR = 2, PD045 = REV = 3, PD070 = 0-10V = 0 etc?

14-09-2019, 11:13 AM
Cheers Doddy, thats what i thought but its always better to have a second opinion!
I have set pd001 and pd002 to accept external commands but I never changed the others...i'll take a look at those values and see what they are set at. What do the forward/reverse PD044=2 and PD045=3 values refer to?

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14-09-2019, 11:21 AM
The For/Rev inputs are general purpose, by default bound to for/rev functions but you can remap them to other functions, eg e-stop

14-09-2019, 02:06 PM
Hmm...do I need anything else connected? I have dcm connected to 5v0 ground and isolated outputs 2 and 3 to the for/rev terminals and then I have acm connected to the power out 5v0 and Vi connected to the analogue out on the AXBB but I'm getting no control whatsoever[emoji848]

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14-09-2019, 03:08 PM
The digital inputs to the VFD are referenced to the digital ground, DCM. The isolated outputs that you're using on the AXBB are open-collector outputs to the AXBB's 24V0 supply. So, rather than connect DCM to 5V0 connect it to 24V0. It's possible, of course, that your 5V0 and 24V0 are commoned in any case depending on your PSU wiring.

Question for you - when you enter a M3/M4 command from the MDI on the RUN page, do the corresponding LEDs on P1[2:3] illuminate?, just a check that you're getting the digital drive for the motor selection. Secondly - according to your settings a "M3 S5000" command into the MDI should set the AO1 pin to 10V, and e.g. "M3 S2500" should set to 5V. Does it?


14-09-2019, 03:17 PM

The AXBB manual shows the 24V0 being used as the ground reference to the digital outputs to the VFD controls.

14-09-2019, 03:19 PM
Also, there's a jumper next to the terminals on the VFD that needs to be set correctly.

14-09-2019, 03:44 PM
I have checked the voltage on the Analogue output and it is at zero but I'm wondering if something is set wrong, if you look at the screen below it shows the speed set at 5000 but actual is zero?? Also output 2 and 3 do change state on the AXBB but dont change the leds on the vfd. Also the vfd states to connect 5v0 so will it be ok with the 24v0 connected?[emoji848]https://uploads.tapatalk-cdn.com/20190914/23ee92180ab20d99c5638dd40eb4947b.jpg

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14-09-2019, 03:54 PM
The 5V0 is simply the 0v reference for the 5V supply. Similarly the 24V0 for the 24V supply. You *can* connect these together - it just means that the supplies then share a common reference.

The isolated outputs from the AXBB are (I said Open Collector, from recent posts it's clear these are Open Drain - difference in transistor technologies - FETs vs Bipolar, but ignore that). This does mean though that the output FET Source is connected, in the case of the AXBB to the 24V0 supply. Therefore, to switch the digital input to the VFD (which is to provide a low-impedance path between VFD DCM and FOR/REV) then you need to connect the FET's source (24V0) to the DCM line on the VFD and the drain (O2/O3) to the FOR/REV input on the VFD, or it simply won't work.

One other thing to try, to help diagnose your problem - you're 3-core CY cable - with the DCM/FOR/REV wires - just try shorting the other end so DCM & FOR are connected - you should see the VFD display change (from memory it goes from a flashing display to a solid 00000 to indicate a demand for 0RPM... but that's just a distant memory).

14-09-2019, 04:08 PM
Cheers Doddy, we are getting somewhere! The forward and reverse now function on the vf d but still no speed[emoji848] do I need to connect the acm to 24v0 too or is it something to so with my ucnc setup as its showing actual speed at 0 even though it's set at 5000?

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14-09-2019, 04:13 PM
Nope, that diagram shows the analogue output AO1 referenced to 5V0, so you need to connect 5V0 to ACM (which I believe you said you already did). (or connect 5V0 and 24V0 together).

You could try connecting the VI input to the VFD to the 5V+ supply (obviously, having disconnected it from the AO1 output first). Then M3 should command a 12000RPM output from the VFD (not variable) - that would confirm that the VFD analogue input is correctly configured. And that would leave just trying to work out why both UCCNC and the AXBB aren't playing with the PWM output control. It feels like a UCCNC configuration thing but your screen shot looks basically right. I can dig out my settings for my Starmill (I have UCCNC driving EITHER that or the Sieg, but it's currently wired into the Sieg which has a manual spindle control).

14-09-2019, 04:15 PM
You da man Doddy [emoji16][emoji16] it now works..but the spindle is at half the speed? So so close now

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14-09-2019, 04:20 PM
You da man Doddy [emoji16][emoji16] it now works..but the spindle is at half the speed? So so close now

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With VI connected to 5V+ ?, I'm assuming that's what you're talking about and the rest of this only makes sense if this is what you mean.

So, connecting 5V into a 0-10V input you would expect 1/2 max speed (I assume 12000 RPM).

You now still need to understand how to get 0-10V from the PWM output from the AXBB. I'm AFK for a short while (wife stops play) then I'll google the AXBB manual a bit more. If you can recover the wiring to have the AO1 connected to the VI on the VFD and any further intelligence from your side?

14-09-2019, 04:34 PM
No, it seems the spindle override on the uccnc changed to max 1rpm(probably when I played with the pulley option) the AXBB has a jumper which is supposed to set the output to 0-10v which I have already removed. I need to get ready for a date so I will pick it back up tomorrow but thanks for the help in getting running [emoji4] much appreciated.

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14-09-2019, 06:19 PM
Just a quick update...i decided to change pd070 to input voltage 0-5v and it now works at full speed so I need to figure out why the AXBB is still only outputting the 5v even with the jumper removed or just stick with the 5v control. I'm assuming people use the 10v so it's more immune to noise?

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Clive S
14-09-2019, 06:28 PM
Just a quick update...i decided to change pd070 to input voltage 0-5v and it now works at full speed so I need to figure out why the AXBB is still only outputting the 5v even with the jumper removed or just stick with the 5v control. I'm assuming people use the 10v so it's more immune to noise?

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No that will be fine.

15-09-2019, 01:00 PM
Charlie some of the huanyang VFD's have a jumper to change between 0-5v and 0-10v as well as being able to use the PD70 setting.

15-09-2019, 02:17 PM
It's all working now [emoji16] although I hacked an old cheapo usb gamepad to use the inputs from my pendant and control panel and it seems the spindle is causing some interference which is occasionally switching the coolant on or the spindle off! I need to find another way of allowing all the inputs or stopping the usb gamepad board being affected[emoji848]

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15-09-2019, 02:22 PM
If you believe it's the spindle (and this is not unlikely), then look at the shielding on the cable to to machine - ensure that it's grounded both ends and ensure that controller and machine share a low impedance path to earth. Share a common earth at the controller for the shielding on all inputs to the controller and/or use differential inputs with/without shielding. Get some ferrites on the supply to the VFD, and to the gamepad.

15-09-2019, 02:38 PM
The VFD itself doesn't cause interference until the spindle is running so would it need a ferrite on the spindle CY cable? Also I have already got all shielding running to a central bank of earth terminals on the sun rail but I thought we were only supposed to connect one end...are we meant to earth both ends?[emoji848]

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15-09-2019, 02:47 PM
https://www.emcstandards.co.uk/cable-shield-grounded-at-one-end-only is an interesting read.

Ask 10 people and you'll get 12 different replies.

I work in an industry where EM emissions and susceptibility are treated very seriously, and at relatively high power levels. Power systems (emissives) are typically, within these systems, shielded both ends.

You'll find that as the VFD is placed under load it will present some of the heavier switching currents onto it's supply lines. Hence the ferrites. But, horses for courses.

15-09-2019, 02:53 PM
...but there's not enough popcorn in the world to cater for the ensuring arguments.

21-09-2020, 09:22 PM
i have the same setup anychance you have pictures of the actual connections
on the vfd and the axbb-e because it is driving me nuts


23-09-2020, 12:10 PM
finally got it going no relay needed

removed jumper then

A01 = VI
ACM = 5V0
DCM = 24V0
FOR = pin 7 port 1
REV = pin 8 port 1

pid001 on vfd = 1
pid002 on vfd = 1