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ACC24E3 and Copley Junus
#1
We want to use the Acc24E3 with digital PWM output to control a Copley Junus drive that accepts torque or velocity commands over PWM. This is different than a direct-PWM power block amplifier because the Copley will be closing the current loop instead of the PMAC. I could not find information in the Acc24e3 manual on how this should be setup as it only covers power block direct-PWM and step/direction configurations. Do we simply skip the ADC signal setup steps in the power block config? Please advise.
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#2
For these drives, the velocity or torque command value is encoded as a (single-phase) PWM duty cycle instead of an analog voltage. If you have the digital amplifier interface board, you can use any of the 4 output phases A, B, C, or D by setting Motor[x].pDac to Gate3[i].Chan[j].Pwm[k].a, where k is 0, 1, 2, or 3 respectively. If you have the analog amplifier interface board, you can still use the D phase pulse output from the encoder connector when OutFlagD for the channel is set to 1.

Use the PWMTOP signal pair (DIR signal pair on the encoder connector) to connect to the amplifier.

Make sure the phase used is configured for PWM output by setting the appropriate bit of the channel's OutputMode parameter to 0.

The range of numerical commands for the PWM circuit is -16,384 (0% duty cycle for TOP) to +16,384 (100% duty cycle for TOP). Set Motor[x].MaxDac to 16,384 to use the full range. (I am going from memory here that the drive treats 100% duty cycle as the maximum positive command and 0% duty cycle as the maximum negative command.)

Set the channel's DeadTime parameter to 0, as this is not needed here.

Set Sys.PhaseFreq and the channel's PwmFreqMult parameters to get a PWM frequency the amplifier likes.

Once you have done this, the rest of the motor setup should be the same as for analog output for velocity or torque mode.
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#3
Thanks Curt. I'll try this out and update the thread with results.

My understanding is that the IDE System Setup for motors does not support this torque/velocity over PWM mode. I have a few partners that plan to use the system in this way. Do you have plans to add this support in a future release of the IDE, and if so when?
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#4
The IDE System Setup does not presently support special cases like these, and there are still other higher priorities for addition to it, so we have not made definite plans yet on this. The Copley Junus manual has the setup directions for the older PMAC and its ASIC; I expect these can be updated shortly in an app note.
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#5
I am resurrecting this old thread because I found out that Copley drives can accept also 2-phase PWM signals when PMAC is doing the commutation.

This way they work pretty mush as a sinewave commutated drive using PWM signals instead of 2-phase analog, but I'm having a hard time finding how to configure ACC24E3 to correctly output the 2 PWM signals.

I'm pretty sure this works with ACC24E3 (digital) but was wondering if we could use PULSE and DIR signals present on all ACC24E3 flavors with quadrature encoder since I am already using this kind of board (ACC24E3A)
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#6
Quote:I'm pretty sure this works with ACC24E3 (digital) but was wondering if we could use PULSE and DIR signals present on all ACC24E3 flavors with quadrature encoder since I am already using this kind of board (ACC24E3A)
This would require significant changes to the 24E3 that are not possible.
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