Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Changing a motor's sense of direction
#1
Can I change the direction a motor considers positive?
Reply
#2
To Change the sense of direction on a motor, assuming that all settings are correct and we only want to change the direction:

1. Brushed Motor (No Commutation, No Current Loop)
Gate1[m].Chan[n].EncCtrl = 3 (or 7)
Gate1[m].Chan[n].OutputPol=1

2. Brushless Motor ( Commutation, No Current Loop)
Gate1[m].Chan[n].EncCtrl = 3 (or 7)
Motor[k].PhaseOffset= - Motor[k].PhaseOffset
(Note: if sinusoidal commutation is done, Motor[k].PwmSf will always be 32767. This will make Motor[k].MaxDac to control the maximum magnitude of voltage output from 0 to 10 volt with a setting of 0 to 32767)


3. Brushless Motor ( Commutation, Current Loop)
Gate1[m].Chan[n].EncCtrl = 3 (or 7)
Motor[k].PwmSf= - Motor[k].PwmSf
Motor[k].PhaseOffset = - Motor[k].PhaseOffset


Phase reference error bit has been replaced by phase finding complete, which needs to be satisfied (by issuing a $) before the motor is allow into closed loop mode.

Also the Motor[k].PhaseFindingStep will tell you what step the phasing procedure is in, or reports an error by reporting a negative value.
Reply
#3
Note:

When doing a sinusoidal commutation, in order to get the full DAC output, you have to set Motor[k].PwmSF=32767 so that Motor[k].MaxDac would control the maximum output voltage with a range of 0 to 32767.
Reply
#4
Here is a document explaining all different methods you can do for this purpose.


.doc   Changing Motor Direction Sense.doc (Size: 37 KB / Downloads: 78)
Sina Sattari
Chief Engineer
Delta Tau Data Systems, Inc.
Reply
#5
If using this method

1. Brushed Motor (No Commutation, No Current Loop)
Gate1[m].Chan[n].EncCtrl = 3 (or 7)
Gate1[m].Chan[n].OutputPol=1

and the "Gate1[m].Chan[n].OutputPol=1" is actualy writing to the register decribed in the Macro 16 SRM as "MS{node},MI917 Output n Invert Control"

I have run into problems where the Option 1 board on the ACC24-E2A will NOT output any DAC voltage if the output is set to invert.

John
Reply
#6
(12-01-2009, 10:12 AM)JohnR Wrote: If using this method

1. Brushed Motor (No Commutation, No Current Loop)
Gate1[m].Chan[n].EncCtrl = 3 (or 7)
Gate1[m].Chan[n].OutputPol=1

and the "Gate1[m].Chan[n].OutputPol=1" is actualy writing to the register decribed in the Macro 16 SRM as "MS{node},MI917 Output n Invert Control"

I have run into problems where the Option 1 board on the ACC24-E2A will NOT output any DAC voltage if the output is set to invert.

John

John,

This depends on the type of DAC chip which is used on the accessory. Some of the earlier chips Delta Tau used, did not support this feature, which would result in getting no output from the DAC. The easiest way to change the sense of direction on the brushed motors for such is system is to change the encoder decode and swap the motor leads on the amplifier or swap the command signals going from DAC output to amplifier input.
Sina Sattari
Chief Engineer
Delta Tau Data Systems, Inc.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)