USB 6008/6009 multichannel simultaneous DAQ

[slarkin712]

I am working on project that will acquire data from 4 inputs (voltage) simultaneously ( two are rs232 from an OEM and two are not) which are for biomedical applications.  I am in possesion of the USB 6008 and 6009, but it appears that these will not allow for simultaneous data acquisition.  I am a student looking for a low cost solution that is portable and can gather data from at least 4 inputs.  Any suggestions?

[Dennis_Knutson]

You say that two of the inputs are from RS-232 connections. These will require two separate serial ports on the computer and won't be truly synchronous with any DAQ device unless you can trigger everything at once. The USB devices you have support digital triggering I believe, but if you truly have to have simultaneous capture, you might want ot look at the USB 5132 for the other two signals.

[Wilfried_71]

Maybe you can have a look on the cDAQ 9172 8 slots carrier (maybe with the 9162 1 slot carrier, if the module is compatible) with the 9215 module that includes 4 synchronous input channels.

[Neal M]

Hello slarkin712,

To clarify the problem a little, it appears to me that the fact the two inputs are serial is not significant in this application and you are just interested in treating them as analog inputs to simultaneously sample 4 voltages. 

If this is the case, the reason that your USB 600x devices cannot do this is because it has only 1 ADC.  This means that it can only read one channel at a time.  You can control the interchannel delay of the convert clock to minimize the time between samples on the 600x devices, but then you can get ghosting and other signal issues.

If you want truly simultaneous readings, it appears that the USB-9215 is the way to go (its the cDAQ 9215 in a USB carrier). It has 4 ADCs so it can truly take all 4 points at the same time.

If I assumed incorrectly and you are using serial communication, then the solution the Mr. Knutson suggest would most likely be the best.

If you want more help with deciding on the best system to use, I would recommend contacting our Technical Representatives.  They can work with you to find the best solution.  They are very good at this and extremely helpful. I hope this gives you a good place to start. Let us know what you decide to go with!