using LPT to generate pulses

[Sairaj]

hi..
im new to labview,
im trying to generate clock , strobe and data signals
( data to be user defined ) using the wave form generator function in LabView 7.1..the data has a different time period as compared to the other pulses..
my end purpose is to use the parallel port to output these signals on an oscilloscope....
could u please suggest how i should go about it?
thank you,
Sairaj.

ps:i have attached the file tht generates the pulses, i have no idea how to use the parallel port after this, especially considering tht there are so many timing issues involved.

Message Edited by Sairaj on 06-09-2005 01:00 AM

[becktho]

Hi Sairaj

There have been several threads about this topic. Just search the forums with "parallel port" and you will find lots of these threads.

Thomas

[Sairaj]

hey Thomas,
thanks for the reply..
i went through the various posts but i really did not find ne to suit my aplication....
i will be using the three signals to control the 74HC4094....more assistance would be greatly appreciated as ive been stuck on this for quite some time now..
thanks,
Sairaj.

[wha@atmel]

hey retour to sender above...........

I have a question:

For what reason do you want to clock Data into a serial to parallel converting Chip while you could use the LPT - Port in direct way for your 8 Bits........up to now I do not understand the need of this 4094.

Do you want to plug some of these 4094 Chips in series ? Do you have the need of more then 8 Bit in Parallel?

Tell me / others some more about your target; then the answer might be more accurate.
By the way......... your vi is very academic for that, what you want to do. There is no need to use waveforms

Take the OutPort.vi from "Advanced / Port I/O" Palette and send one Byte to Addr. 0x378 (typical)- that's it.

Regards
Werner

[Sairaj]

Dear Werner ,
thanks for the reply,
u guessed right, i will be needing 2 of the 4094's in series....
i figured as much about the waveforms....
basically i want to use three data pins on the parallel port to generate three signals (but they have different time periods, there are issues about setup time and hold time etc. how do i get around that??) i hope my situation is properly explained..
your help will be greatly apreciated sir,
thank you,
Sairaj.

[wha@atmel]

what a stupid shi...... - NI cancelled the attachment during preview post - here again.......



hi retour,

find attached a modified vi ( was for AD9835 - numerically controlled Oscillator ).
You should be able to understand the principle and change these vi's for your needs.

My intention was - to be fast and copy things together.................

regards
Werner

[Sairaj]

Dear Werner,
thanks a lot!!!!
really appreciate your efforts in helping me out!!
i am going through your comprehensive code now..will get in touch with you if i cant understand something..
thank you once again sir,
regards,
Sairaj.

[Sairaj]

Dear Werner,
could you please tell me what pins on the parallel port i can get the clk, data, and strobe pulses? i was monitoring the output on an oscilloscope today and got meaningful pulses only on one pin ( i couldnt make out which pulse it was though.... )
also, if i want to modify the time period of the above mentioned pulses, how do i do that?
thank you again,
Sairaj.

[Sairaj]

p.s.: i got the time period part ....
please help out with the pin #s though....
thanks..

[wha@atmel]

Hello Sairaj,

...the time period and the digital graph is cosmetic only - should show, how this SPI works in principle.

The timing of LPT-Port you cannot influence from LabVIEW (only in millisec. range are wait-states possible).
There are some marginal tricks possible - use the OutPort-sub.vi twice or some more times with the same input;
then you can slowdown the operation speed - but never increase........

I can't understand your problems - in Diagram every single line of DSUB25 is described - what do you need
in Addition ?? strobe = D0 (Pin2) ; clk = D1(Pin3) ; Data = D2(Pin4) Ground = Pin 18 .....25

Take a scope - connect to lines above and you should get the nearly the same picture as the one in Diagram -
(expect slower timing ).

Regards
Werner