Kinetix 300 velocity accel but no decel

I am trying to set up a Kinetix 300-Micrologix 1100 system. I have most of the bugs worked out but I am stuck on something.

I am communicating with the drive in velocity mode over Ethernet using messaging instructions. I enable the drive, send it a speed and it accelerates to that speed per the acceleration rate that I set in the MotionView software. When I want to stop the drive I disable it. It immediately stops. No decel. No ramp. It is as if I sent the drive a "0" speed. It does not matter what I set for a decel rate. Accel I can change so I know that it is active.

Any idea why I am not getting a decel? Is there another way to stop in velocity mode besides disabling the drive? If that is the only way then is there a place to change what happens when I disable the drive? I did look in the manual but it only tells you how to start not how to stop.

Thanks in advance.

Disabling a drive is what you do when you have a fault. You want the drive to stop quickly. Try telling the drive to go to 0 speed instead. This way it will this way the motion profile generator will stay active and should generate a ramp from the current speed to the new speed you specified.

Thank you. That did it. I will just keep the drive enabled.

It shouldn't drift, correct? I remember old analog drives from years ago drifting at zero speed because "zero" volts is not always zero.

lurby said:

It shouldn't drift, correct? I remember old analog drives from years ago drifting at zero speed because "zero" volts is not always zero.

Click to expand...

In theory it shouldn't drift but in practice it will.

If holding position is critical then position control may be a better option. You can still tell the motor to move at a desired speed.

Our controller has two modes for speed control. One is a pure speed control where the controller doesn't care about position at all. The other is one where we just bump the position by the amount necessary so the motor moves at the desired speed. When we stop bumping the position the motor will hold whatever the current position is and not drift.