Input_Pos keeps resetting

1

Hi,

In a forever while loop after assigning a particular input position, if I check if the input pos is equal to that assigned position, this returns false and if I print out the value it shows that the value set previously was reset. Not sure what’s going on here?

Also in the position control mode, if a new Input Pos is set while the motor is moving, I get a OVER CURRENT error. (The new value is in the same direction as the movement of the motor and far from the setpoint)

2

Please provide some examples of what you’re writing vs what you’re reading.

Also, what is your controller.config.input_mode setting?

3

I’m in the pass through input mode, basically controller.config.input_mode = 1

Here’s my function:
def MoveToSetpoint(self,Pos,CurrAngle,TargetAngle,retry = 1):
if self.CheckDeadBand(CurrAngle, TargetAngle): # Allows movement if outside deadband range
if self.get_error() == 0:
if self.axis.requested_state != AXIS_STATE_CLOSED_LOOP_CONTROL:
self.axis.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL
while retry != 0:
if int(self.controller.input_pos) not in range(int(self.Pos)-2,int(self.Pos)+2):
self.EndTime = tim.StartTimer(‘1s’)
if tim.TimerElapsed(self.EndTime):
print('Entered '+ str(self.controller.input_pos))
self.controller.input_pos = self.Pos
self.TargetAngleSet[TargetAngle] = True
time.sleep(0.25)
retry = retry - 1
else:
return True
return False

This function receives, Pos inputs in a forever while loop, I have a check the prevents the same Pos from being set as controller.input_pos over and over again.

Here’s the debug output:
Pos:7411
Entered -8.438212535111234e-05
Pos:7764
Entered 490.2388000488281

There are two issues here:

  1. The controller.input_pos before being written to should’ve reported 7411, but it is reporting 490.238 which is likely the odrive’s current position
  2. The moment the Pos 7764 is written to controller.input_pos, there is a CURRENT_LIMIT VIOLATION ERROR that pops up. Basically I can’t write new input_pos values in the same direction of rotation. I have to wait till the odrive comes to a stop. Is that normal?
4

Hi any update?

5

No that’s not normal. You want to go to 7000 rotations position? Make sure vel limit and current limit and torque limit all look ok