one task control multiple DAQ modules

[quexin]

Is it possible to have one task control 2 or 3 DAQ modules? I do not seem to have luck in doing so.

Also, for a digital output NI device that sources voltage, if I hook up 10v to it and the module has 10 channels, how on earth are the 10 channels each able to source 10V, when I only supply one 10v power supply.

Does it just send extremely small amounts of current per channel versus sending a decent amount of current per channel if I just had one output on?

[crossrulz]

You need to be A LOT more specific.  What modules are you using that you want a single task for?  What digital output are you using?

[Sam_Sharp]

It depends on the DAQ module - some of the higher end modules allow you share tasks of the same type (e.g. analogue input) across devices but most of them you have to create one task/channel per type and per device.

As for the digital outputs - the datasheet of the device will tell you how much current the output can source - it won't be very much! Some of the modules have a fixed rating per channel (e.g. low current digital communications devices) and some have a rating that depends on the number of channels that are active (e.g. higher current drive modules). If you exceed these ratings, the module will either shutdown to protect itself or you may risk damaging the module.

[JDragon]

You can read/write from multiple modules in a single task using Channel Expansion.

Which NI digital output device are you using? 

[quexin]

Hey all,

This is a crosspost, I posted somewhere else after posting this post, just because I did not know whether I posted in the right place, here is the link to the other in case anyone else comes across this problem: http://forums.ni.com/t5/Multifunction-DAQ/one-task-control-multiple-DAQ-modules/td-p/3170766 Sorry about that.

Anyways, I have 

NI 9401, 

NI 9403,

NI 9474,

NI 9375,

I am using a 

NI cDAQ-9184 chassis

I believe these are all compactDAQ.

I would like to combine the 9401 and 9403 into 1 task, and the 9474 and 9375 into 1 task.

Also, I am having issues with one of the modules, the 9375. When I wire False data to the Write DAQ on LabVIEW it seems that the 9375 is still sourcing some voltage. I cannot remember the difference in voltage of then I wire true data versus false, But I believe they were somewhat close. Has anyone came across a problem like such?

[JDragon]

Hi Quexin,

All of the cards you mentioned are digital I/O. Unfortunately the cDAQ can only perform 1 DI task and 1 DO task at a time. In addition, the only way you can perform Channel Expansion is with Analog Input.

Here is a link describing the task specifications for CompactDAQ Chassis.

http://digital.ni.com/public.nsf/allkb/5E0B829E50ADE1BC86257AC50062B2D2

I also highly encourage you to create a new thread if you have other questions. Your questions will have better visibility and will get resolved faster