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7i33 with 7i96 firmware with one pwm in step04
12 Apr 2023 19:06 #268922
by COFHAL
7i33 with 7i96 firmware with one pwm in step04 was created by COFHAL
Install the firmware 7i96_1pwm.bit to be able to use the PWM output to connect it to the 7i33AT card, with this configuration I can control an MPA-07 driver of an AC servo motor that is controlled with +- 10 volts. The problem I have is that at the output of DRV0 I only have an independent voltage of -10 volts when I try to reverse the direction of rotation with M3 or M4. The connection I have for the PWM signal is the following: TB2: 2 PWM - to GND 3 PWM+ to pin 15 J1 (50 pin header connector). I also have the encoder output of the MPA-07 drive connected to encoder 0 of the 7i33AT, I have encoder feedback and everything works correctly, I can control the speed of the servo, but only in one direction.
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12 Apr 2023 20:05 #268930
by PCW
Replied by PCW on topic 7i33 with 7i96 firmware with one pwm in step04
1. You should never ground any step/dir pins, this shorts the driver chip output
2. You need the direction signal to get +- outputs
2. You need the direction signal to get +- outputs
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13 Apr 2023 18:57 #268988
by COFHAL
Replied by COFHAL on topic 7i33 with 7i96 firmware with one pwm in step04
Thanks for your support, the DIR pin connection was wrong that's why the servo only rotated in one direction. Now my problem is that the commanded speed does not match the actual speed at which the servo is turning. For example, if I type M3 S100 automatically, the speed jumps to 1600RPM. When checking with a tachometer, it reads the same speed as the encoder reads (1024 resolution). I also check the value of the voltage that commands the speed and it is fine, for example the maximum speed of the servo is 3000 RPM, that is, it would give 0.0033 volts per rev. and when I type M3 S100 the voltage that I measure at the output of DRV0 is 0.33 volts, that is to say that the control voltage corresponds to a speed of 100RPM but the actual speed at which the servomotor rotates is much higher.
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- besriworld
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14 Apr 2023 21:53 #269041
by besriworld
Replied by besriworld on topic 7i33 with 7i96 firmware with one pwm in step04
You should see the servo driver settings/scale
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