Feedback value in Torque Mode without main battery (HBL1660)

7 years 3 months ago - 7 years 3 months ago #29531437 by gg
I am running HBL1660 from Power Control, with a braking resistor in place of the main battery.

In the Run tab, I monitor Battery Amps, Motor Command, and Feedback while manually spinning the motor.
At PWM=0 the motor is shorted and hard to spin. At -1000, the motor is easy to spin in the backwards direction (and at 1000 in the forward direction).

When I have the Torque Mode enabled in the motor config, I get both a Battery Amps reading and a feedback reading in the Run tab. In Open Loop mode, there's only the Batter Amps reading and no Feedback reading.

Question: what is this Feedback reading? It has the opposite sign of the Battery Amps reading (Batt Amps are negative and Feedback is positive) and the Feedback values are slightly different than the Battery Amps values. How is this Feedback value calculated and what sensor is it coming from?

And second, how should an Input be configured (Motor Command, Feedback, etc.) to serve as the Set Point for the Torque Mode (i.e. to serve as the desired value based on which the Torque Mode will adjust PWM) when a resistor is in place of the main battery?

Thanks.

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7 years 3 months ago #29531438 by niko
Hello,

The feedback in torque mode is: (MotorAmps * 1000)/AmpsLimit.

About your second question, if you use a script you can manage that.
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7 years 3 months ago #29531440 by gg
Ok. So Feedback = MotorAmps * 1000 / AmpsLimit. Is MotorAmps = BattAmps / PWM, where PWM = (from 0.2 to 1) ?

As for the second question, can you give a quick example?

And if my AIn1 has a 5K pot and is configured as Mortor Command, will the Torque Mode use that as a Set Point, comparing it to Feedback to manage the current when the main battery is disconnected?

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7 years 3 months ago #29531441 by niko
Hi,

If you see the user manual, how we can acquire the data of the inputs, you might get some ideas. Yes you can use analog as motor command, as long as pulse input, but I cannot get into details since I am not aware of the setup.

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7 years 3 months ago #29531442 by gg
Well, the user manual is not helpful because it does not disclose the script of the Torque Mode. I am asking about the inner workings of the Torque Mode.

Once again, the question is which two values does the Torque Mode compare and what function does it use to control the current?

Does the Torque Mode compare a Motor Command (on Analog or Pulse input) with Feedback (scaled MotorAmps, where MotorAmps is based on the actually measured BattAmps) and apply the _GO function (-1000 to 1000) to control the current?

Is there a specific function (similar to _GO) that just changes the PWM duty cycle and works even when the main battery is replaced with a resistor? Thanks.

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7 years 3 months ago #29531444 by niko
Yes and Yes (that function is _GO)
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