topic Re: control motion in LabVIEW

control motion

aSquared — Mon, 21 Sep 2009 07:36:36 GMT

I will appreciate help in this:I use LV DSC RT 8.2.1. I have motion control system of the following devices: PXI 7350 connected to UMI 7774 and stepper driver P70360. I use stepper motor T21NRLC-LDC-NS-00. The P70360 configuring is NI NEMA 23, (s1=1,s2-1=off), the resolution is 5,000, load inertia is 0-1, Dynamic smoothing is minimal, current reduction is Enabled, multistepping is Disabled and encoderless stall detection is disabled. Connecting to AC power (J7) is 240 VAC. the stepper motor connected to the drive J6 : orange wire to pin 1, black to pin 2, yellow to pin 3, red to pin 4 and green/yellow to pin 5. The UMI 7774 connected to the drive in the axis 1 and 2 control 15 pin D-type. the limit led is active low and the fault and enable is active high. I use two motor and they are working properly with MAX and with simple VI. My problem is that the motor are getting over heated, also when they are not moving at all. Thanks for any help.

Regards

amitai abramson and ilan eliyahu

Re: control motion

Cory_K — Mon, 21 Sep 2009 20:36:31 GMT

Have you ever gotten the motor to move or not?
You said it was working with a simple VI, but then said it is not moving at all.

The motor's over-heating doesnt sound like a software issue, so you cant do much about that in LabVIEW .

However, if you post your current VI, we can help figure out why the program isnt working.

Re: control motion

AnalogKid2DigitalMan — Mon, 21 Sep 2009 20:43:58 GMT

I'm thinking that the nominal current and peaks are configured too high in the hardware (jumper settings). For steppers, there is usually also a setting to reduce current (holding torque) when not in motion to reduce heaing during standby.

-AK2DM

Re: control motion

aSquared — Wed, 23 Sep 2009 06:20:57 GMT

Hi Cory k

thank you for your response,

I use two motor and they are working properly with MAX and with simple VI. they are over heated also when i connect them to the electricity and not moving them at all.

ilan

Re: control motion

aSquared — Wed, 23 Sep 2009 08:11:50 GMT

Hi AK2DM

Thank you to for your response,

We aware to this point but the only setting that we found in the jumper settings was the current reduction in the stepper driver P70360 and we set it to Enabled.

ilan

Re: control motion

Brian_Beal — Wed, 23 Sep 2009 10:37:21 GMT

Are they smoking? Stepper motors run hot, so don't be too concerned if they feel hot. Are you saying that the motors work in MAX, but not in your application program?

Re: control motion

AnalogKid2DigitalMan — Wed, 23 Sep 2009 15:19:33 GMT

Have you set the DIP switches to match your motor model # as outlined in section 3.1 of the manual?

http://www.ni.com/pdf/manuals/P70360manual.pdf

-AK2DM

Re: control motion

aSquared — Thu, 24 Sep 2009 06:55:35 GMT

HI Brian beal and AK2DM

Brian, the motor are not smoking, they are working in MAX and in application program.

AK2DM, I think that the setting of the DIP switches match the motors as outlined in the manual, for the stepper motor T21NRLC-LDC-NS-00 : NI NEMA 23, (s1=1,s2-1=off), the resolution is 5,000, load inertia is 0-1, Dynamic smoothing is minimal, current reduction is Enabled, multistepping is Disabled and encoderless stall detection is disabled.

Thanks for the help

ilan

Re: control motion

Brian_Beal — Thu, 24 Sep 2009 10:13:29 GMT

OK, I think I understand. Everything works as it should, but the motors are getting hot? Steppers do get rather hot, and even with current reduction, will generate heat at a standstill. Even if the motor isn't moving, current is flowing through it. If you don't move it for a long time and it still gets hot, then maybe the current reduction isn't working.