Duty cycle on SCXI Modules

[Charel]

Hi All!
I was wondering if anyone could tell me if there is an SCXI Module available that allows me to adjust multiple duty cycles. I need to control the duty cycles of multiple signals simulataneously and was hoping to find a module to do this with. It should be a module that fits to an SCXI housing because this is the system that I am currently using for the measurements. A single module containing multiple counters and counter outputs would be ideal.

I am sure I am not the first to need something like this, so could someone please help me out and tell me how I can solve this?

Thanks to everyone for the help!

Regards
Charel Marais

[Wolfgang_Z.]

Hello Charel,

Do you think with Duty Cycles a PWM (Pulse Width Modulation)? Normally for a PWM you are using counter. Dependend of your SCXI hardware you can use maximum 2 Counters.
At the moment do you use a SCXI-1600 (USB), a 60xx or a 62xx for data acquisition? SCXI systems are designed for signal conditioning. If you need more counters you should use a counter board like NI-66xx series.
More information about the boards you can find here:
http://sine.ni.com/nips/cds/view/p/lang/de/nid/4553

Regards
WolfgangZ

[Charel]

Hi Wolfgang,
Yes I was thinking of PWM for the duty cycle control. I have done this before using counters on the NI cards, but as you mentioned it is only possible to control 2 signals. I now need to do at least four, possibly more. The system I am using now is a 6036 PCMCIA card as acquisition connected to an SCXI 1000 with an 1102, 1126, 1163R and 1124. I have considered using another DAQ card to provide more counters, but this is a very untidy solution when you have two PCMCIA DAQ cards in one notebook each with a cable going into it. The connectors push very hard against eachother and in long term use, this will destroy the connectors on the cables, the cards and the notebook.
I gather that there is no SCXI module available that provides counters as a normal "slide-in" module (like an 1102 for instance)...? Is there then some other effective way to connect two PCMCIA cards to one notebook?

Thanks for the advice on the counter cards.

Regards
Charel

[Wolfgang_Z.]

Hello Charel,

At the moment there are only PCI and PXI boards available with more than two counters. Generally the PCMCIA and USB boards has only 2 counters. There are no counter modules for SCXI because SCXI is only for signal conditioning.

Regards,
WolfgangZ