PWM in Motion Control

[mayihelpu]

HI All,

I am facing a problem in Motion Controller.

We are using PCI 7344 and UMI 7774.

Now their is a connector on the Motion control card for Digital I/O.

In this Pin No 5 and Pin No9 are PWM1 and PWM2 respectively.Now I have used to VI PWm duty and config PWM. I am seeing the PWM waveform on CRO.But to my surprise the output is not matching the required data.

IF you go for HElp and click config PWM VI block , you can see a table given where the internal clock selected corresponds to a particular frequency in 734X and 735X.Now since I am using 7344 my frequency should match with 734X table , whereas this is not happening and

my frequency matches the table of 735X.

SO i am bit confused about the controller specs or is someor the other way Iam missing some thing more.

Regards

Manish Karnik

Cruiser Controls

Mumbai.

[Jochen]

Manish,

since the latest change of the hardware revisions the 734x use the same basic system architecture as the 735x boards. So what you see should be intended behavior. I'll check with our motion R&D group if there is a documentation issue that needs to be fixed.

Sorry for any inconvenience.

Best regards,

Jochen Klier
National Instruments Germany

[mayihelpu]

Hi Jochen,

Thanks for your reply.

It would be better if their is a firm documentation on this as their will be no misleadings further.

Thanks.

Regards

Manish Karnik

Cruiser Controls.

[Jochen]

Manish,

please have a look at this table which comes with the NI Motion function help file for NI-Motion 7.2. This table should contain the correct values. The latest revisions of the 734x are named 7340 and the PWM output should follow this table.



Best regards,

Jochen Klier
National Instruments Germany

Message Edited by Jochen on 07-05-2006 01:34 PM