I am using a PCI-7356 motion card. When running axis 1&2 servos at constant speed, axis 1 sometimes stops and moves in reverse direction. What would cause this?

[Jochen]

John,

there is no normal operation mode that would act like that and I have never heard about a similar issue. Here are some ideas and questions that come to my mind:

• If for some reason an axis reverses the direction in the middle of a move, a following error should occurr very quickly. Does this happen?
• If you switch the cabling for axis 1 and 2, does the problem stick with the physical axis or with the controller's axis number?
• Do  you get any unusual status information (e. g. in 1D interactive in MAX) when the error occurrs?
• What type of drive and motor are you using? Are you using a quadrature encoder or do you get an emulated feedback signal from a servodrive for brushless motors?

Kind regards,

Jochen Klier

National Instruments

[John524]

Jochen, thank you for your response.  I have been away from the office for a week.

I sent the motion card back to NI for evaluation because it was also causing the computer to crash and automatically reboot.  I think the two problems may have been related.

I did switch the cables, and the problem always remained with axis 1.  I don't remember any unusual status information from MAX, and I had the following error setting disabled at the time. 

I am still waiting to hear the results of the testing from NI.

[Jochen]

John,

in this case a defective device is probably the root cause of the problem and sending the board for repair should be the best option.

Please let me know, if the issue persists after the repair process.

Thanks,

Jochen