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Author Topic: Spindle Direction Control, 7766 controller  (Read 818 times)

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Spindle Direction Control, 7766 controller
« on: March 26, 2019, 03:53:42 PM »
I believe there may be a hardware problem with my 7766 controller. I have used this controller for a few years. It has performed flawlessly, but I now need it to drive a spindle as well.

Axis-5 has been configured as spindle per the 7766 setup manual. I am able to verify the configuration by measuring the analog output with DVM, and observing the Hicon Status Panel.

 The analog output responds to M3 command, 0-10VDC as expected when speed variable is applied. Likewise, the Hicon Status panel confirm the pulse counts on the axis increase in the positive direction, and the pulses quicken and slows as the speed variable is applied.

So as I apply the M4 command to rotate the spindle counterclockwise, there is no Analog Output present. But as I observe from the Hicon Status panel, pulse counts are identical to that from the M3 command, except in the minus direction.

Upon starting the computer and controller this morning, the Analog Output under the M4 command began working. I cycled the Analog Output several times each between M3 and M4. After a while the Analog Output failed with the M4 command applied. Sometimes you can see the output drive to about 2VDC, then it will drop back to 0VDC. But the analog signal always performs from the M3 command.

Have you seen this before?

Have I overlooked something in the setup?

And if there is a hardware problem, is the board serviceable?

Thanks in advance,

Re: Spindle Direction Control, 7766 controller
« Reply #1 on: March 26, 2019, 04:59:17 PM »

When you issue the spindle speed gcode command (ie S1000), do you see the message "New Spindle DAC Voltage Transmitted..." in the black debug or command window that opens with Mach4?

The DAC hardware does not differentiate between the M3/M4 command. It only outputs the 0-10V voltage it is told from the spindle speed command.

The spindle direction is determined by the Mach4 output mapping (ie Spindle FWD to relay 1, spindle REV to relay 2).

The DAC hardware is serviceable on the board if the component is the issue. 

You can send an email to support or give us a call at the office if you'd like.
Re: Spindle Direction Control, 7766 controller
« Reply #2 on: March 26, 2019, 11:17:30 PM »
Thank you for the quick reply.

The control software is Mach3. Per the setup instructions, M3 is set to relay 1, and M4 is set to relay 2.

I agree with you about the outputs. M3 and M4 should provide identical analog output signals for the same given command speed.

Both relays worked well yesterday morning. Each provided linear output voltage relative to speed. After the board warmed up, about five minutes or so, relay 2 stopped providing analog voltage regardless the commanded speed.

I am not familiar with Mach4 or the Hicon status messaging from Mach4. However, the Hicon Status panel provides feedback for Spindle Speed. A counterclockwise/speed command looks like this: New Spindle Axis5 Velocity 5.06329, Accel4, Direction -1    (set at 50% max RPM or ~5.0VDC output)

In my case, it appears the 'Software side of the house' is working, but the 'Hardware side', at least relay 2 is not.

Re: Spindle Direction Control, 7766 controller
« Reply #3 on: March 27, 2019, 10:48:36 AM »

If you think it is the hardware and you would like us to take a look at it, please either send us an email or call our office so we can start the repair process.