PXI-6542 bidirectional

[Steve_Block]

I would like to use the PXI-6542 for an application where some samples need to be read and some need to be write. I2C for example. Is there a way to configure a channel to read at certain points in time and write at others or do I need to connect two channels to the same signal to do this.

[Steve_Block]

Just to clarrify my question, can a channel be configured for both dynamic acquisition and dynamic generation at the same time?

[EEsRULEtheWORLD]

Hi, Steve.

Yes, the PXI-6542 can be configured for dynamic generation and acquisition.  There is a great example for this in LabVIEW located under Help»Find Examples.  It is called Dynamic Generation and Acquisition-Demo.vi.  This example will generate a waveform continuously on selected channels.  Acquisition on these channels will be initiated on a pattern match.

[Raajit_Lall]

Steve,

To add to what Sara mentioned, the PXI-6542 can be used for generating and acquiring on the same channel but will only be software controlled.  For something like I2C the 6542 might not be the best choice since I2C required per cycle I/O capabilities.  I would recommend using the NI 655x devices for this application.  The 655x devices can be configured for changing state on a pin on a per cycle basis (the 6542 is not capable of this).  

We even have I2C libraries written which you can use with the 655x devices.  Here is a link to these libraries. 

I2C Digital Waveform Reference Library

Another option is an FPGA based solution.  The NI PXI-6581R has an onboard FPGA, on which you can implement the I2C protocol.  This device can change state on a per port per channel basis.

If you do not need per cycle state changing capabilities the 6542 will work as well.

Thanks.