7i76e Analog 10v Spindle output not working

I am trying to get the 7i76e to output an analog signal for my spindle, and it is not working.
My spindle driver takes an analog 0-10v signal (I have tested that my driver works - I used a variable voltage supply as the input, and the motor spun).
I configured the 7i76e using PnCConf, but when I try to do openloop test in PnCConf, or turn on the spindle in LinuxCNC, nothing happened.
Measuring the voltage on TB4, all the connections are 0v (with respect to TB4.1)

I have 32V as field input into the 7i763. I have an E-Stop button that is wired to TB6 that works.

What can I try to debug this situation?

I have also attached my ini and hal files, just in case.

1. 32 V (unless its very well regulated) is rather high for field power
2. TB4 pin 3 must be 5 to 12V (nominally 10V) for any output voltage on TB4 pin2
this normally comes from the VFD potentiometer supply

My spindle driver only has a 5V output. I tested it with that, and the I get the analog output to go from 0-5V.
So if I want the full 10V range, I need an external 10V supply? Would it be ok to power it from a 12V power supply?

0 to 5V should be OK if your VFD can be programmed to accept that
otherwise an external 10 or 12V supply can be used

Larry, Did you ever get your spindle control working?

I'm having a similar problem. I can get mine to control the speed from barely moving to real slow and the speed is inverted "+" goes slower "-" goes faster. My controller one of the Chinese ones that comes OEM in a Sieg X3 mill which uses a pot to control the speed. The feed to the pot is at mains level. Open circuit I measure 12.11 volts difference between the positive and negative leads. When the leads are connected to the pot I get a 6.43 difference. When I move the leads to the TB4 terminals I get the following readings.

TB4 - 1 2 3
| 1.01v | 1.94v |
| 2.94V |

with Spindle out at
1 I get 1.1v between TB4-1 &
5001 I get .7v between TB4-1 & 2
10001 I get .7 between TB4-1 & 2
I guess that explains the inverted operation.

PCW - You stated the following:
2. TB4 pin 3 must be 5 to 12V (nominally 10V) for any output voltage on TB4 pin2
this normally comes from the VFD potentiometer supply

0 to 5V should be OK if your VFD can be programmed to accept that
otherwise an external 10 or 12V supply can be used

I'm not using a VFD so this probably would not apply in my situation. In the above scenario a matter of using an external power supply instead of the power coming from the VFD? In my case, since the POT plus and minus voltages are differential at mains level I don't see how I could do that. I'm not sure I even need to giver that open circuit I get 12.11 volts difference between pos & neg.

Well I off to dig for more info. Any help would be appreciated.

John

Hi John,

Yes, I got my motor working. I googled the Seig X3 motor, and some of those pics look like my motor, I'm using a hishine motor similar to this: hishinetec.en.alibaba.com/product/602523...ndle_BLDC_Motor.html
TB1 and TB3 are input pins. So if you give TB1 ground, and TB3 +10V, then the TB2 (the output) can be set to a voltage between 0 and 10V.
In my case, I hooked up GND and 12V from a power supply, I connect the GND to my motor controller, and TB2 to the input signal for my controller.

I'm not sure what you mean that your POT is between the mains level.

Let me know if you need more help.

If you only have 2.94V power the 7I76Es spindle interface will not work.

This probably means the motor control will not supply the several mA of current that the
spindle interface requires.

You can possibly use an ISOLATED power supply (like a wall wart) but you have to be very careful
because its all live. Also some potentiometer controlled motor circuits ( especially SCR circuits )
simple cannot be controlled by a variable voltage.

My understanding is that one the type of speed control in my mill the + and - on the potentiometer is at AC line voltage say - is 108 and + is 120 so whatever you do with these must be isolated. I accidentally grounded the E-Stop lead a while back and blew my speed control. I asked the guy that fixed it about controlling the speed from the Mesa 7i76. This is what he had to say:

Hi John - The key thing to look for is a variable output voltage (0-12 volts) that is optically isolated from ground. If your board can output that, then you will be OK. What gets everybody in trouble is trying to make a direct connection to P1-P2-P3 on the XMT board which will fry everything unless they have optical isolation. -Pete

John - I think you are looking for something along the lines of a C41 interface board. I'm not a CNC expert but you can speak CNC to this spindle control board and it will output a voltage that will control the XMT board in your machine - and it has a couple of relays you could use in conjunction with a reversing relay/switch for direction control

My mill has a potentiometer to control the speed so based in the description below it sounded like I could just swing the leads from the pot to the TB4 terminals. However I understand the issue with there not being enough mA which it why the voltage drops from 12.11 when connected to the 7i76

With the three wires from the controller still connected to the 7i76 TB4. Would I just take a wall wart and connect the negative wall wart lead to TB4-1 and positive to TB4-3?

Thanks
John

7i76
SPINDLE INTERFACE

The 7I76 provides one analog output for spindle control. The analog output is a isolated potentiometer replacement type device. It functions like a potentiometer with SPINDLE + being one end of the potentiometer, SPINDLEOUT being the wiper and SPINDLE- being the other end. The voltage on SPINDLEOUT can be set to any voltage between SPINDLE- and SPINDLE+. Polarity and voltage range must always be observed for proper operation. The voltage supplied between SPINDLE+ and SPINDLE- must be between 5VDC an 15VDC with SPINDLE + always being more positive than SPINDLE-.
Because the analog output is isolated, bipolar output is possible, for example with SPINDLE+ connected to 5V and SPINDLE- connected to -5V, a +-5V analog output range is created. In this case the spindle output must be offset so that 50% of full scale is output when a 0V output is required. Note that if bipolar output is used, the output will be forced to SPINDLE- at startup or when SPINENA is false.

Well I finally got the spindle speed control to work. Not perfect, it still needs some tuning but it looks like I'm getting about 500 rpms more than I get with the manual pot. I still have to get the all of this hal stuff straight in my head but I think t he key here was getting a 12 volt wall wart power supply hooked up to TB4 per PCW's suggestion.

At value 1 on hm2_5i25.0.7i76.0.0.spinout the spindle is still turning very slowly. If I click on the stop button hm2_5i25.0.7i76.0.0.spinout goes to 0 and the spindle stops. I think I read somewhere about someone else that had the same problem.

Thanks Guys
John

JohnnyCNC wrote:

Well I finally got the spindle speed control to work. Not perfect, it still needs some tuning but it looks like I'm getting about 500 rpms more than I get with the manual pot. I still have to get the all of this hal stuff straight in my head but I think t he key here was getting a 12 volt wall wart power supply hooked up to TB4 per PCW's suggestion.

At value 1 on hm2_5i25.0.7i76.0.0.spinout the spindle is still turning very slowly. If I click on the stop button hm2_5i25.0.7i76.0.0.spinout goes to 0 and the spindle stops. I think I read somewhere about someone else that had the same problem.

Thanks Guys
John

Did you ever resolve this issue? I'm setting up a lathe with a DC motor and speed control. I also get 12 vdc across P1 and P2 when not connected but when I connect them to the isolated digital pot on the 7i76 I only get the spindle turning slowly with no control.