LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

PWM Outputs on MCB2300

Hello!

 

I'm trying to generate PWM output signals with the MCB 2300 Board and LabVIEW for ARM 1.0. Unfortunately some problems occured:

-If I use the PWM1 output, no signal is generated

-If I use other PWM outputs, a signal is generated, but changing the frequency in the property dialog has no effect

-Every PWM output has got a different (constant) frequency

-If I use two PWM outputs in a VI, the output signals change in a strange way subject to the input values (Sometimes only one correct singnal, sometimes two signals, but wrong duty cycle value)

 

I'm working in a generic project, the problems occure in a MCB2300 project, too.

 

It would be very nice, if anybody outthere could help me!

 

 

 

Greetings,

 

Joscha

0 Kudos
Message 1 of 6
(2,953 Views)

Hello Joscha,

i have tested this with LV 8.6 and Arm Kit 1.1 everything works fine.

I have added my project as zip file. There is a difference, if you put 

other numerics into the PWM output. You must put in all outputs the 

same numeric so the additional seetings from the frequency take an effect.

Do you use Port 2 also as an input or output for LED`s or KEY´s that 

doesn´t work. How dou you measure the different duty cylces in

my project you can see it on the brightness of the LED´s.

 

best regards ALEX

 

best regards
Alexander
0 Kudos
Message 2 of 6
(2,928 Views)

Hello Joscha,

i have tested this with LV 8.6 and Arm Kit 1.1 everything works fine.

I have added my project as zip file. There is a difference, if you put 

other numerics into the PWM output. You must put in all outputs the 

same numeric so the additional seetings from the frequency take an effect.

Do you use Port 2 also as an input or output for LED`s or KEY´s that 

doesn´t work. How dou you measure the different duty cylces in

my project you can see it on the brightness of the LED´s.

 

best regards ALEX

 

best regards
Alexander
0 Kudos
Message 3 of 6
(2,926 Views)

Hey Alex!

 

Thanks for your message. Unfortunately I can't open your project, because I'm working with older version of LabVIEW (8.5) and LabVIEW for ARM (1.0). 

In my project I'm only using PWM outputs, so there can't be a conflict with other elemental I/Os. In other projects I could use the LED-functions without problems, even LED0, although PWM1 doesn't work at all.

I'm displaying the output signals on an oscilloscope to get information about duty cycle aund frequency.

 

Best regards, Joscha

 

0 Kudos
Message 4 of 6
(2,911 Views)

A question to the forum team:

 

Would it be possible to move this thread to the correct part of the forum (LabVIEW embedded)? Unfortunately I didn't choose the right option, when I was posting the question.

 

Regards, Joscha

0 Kudos
Message 5 of 6
(2,906 Views)

Hello Joscha,

i have make an pictre of my test programm, and here is an link about the offset and the duty cycle.

http://digital.ni.com/public.nsf/allkb/839DB5B54A0915A9862574D70063B64B

In my application the pwm signals start at the same time.

I hope it helps, if not please show me your code. 

best regards ALEX

best regards
Alexander
0 Kudos
Message 6 of 6
(2,885 Views)