I2C 8451 Write Read Issue

[Klepackage]

Hey everybody,

I'm having some issues getting the USB 8451 to work properly.  I currently have connected a MEMS accelerometer using I2C and I'm trying to simply read the WHO_AM_I register to make certain everything is working properly.

The address for this device is 19 (hex) while letting the software take care of the final bit for write/read.

The clock rate is set to 100 kHz.

The WHO_AM_I register is 0F, but the generic I2C Read.vi won't allow that value.  When I run the VI, I don't receive any errors.  I have had errors before that were quite clear (lack of bus seizure, improper address, etc.).  Can anyone help explain why I can't modify this file at all or point me towards a more in depth and robust Read/Write VI?  Thanks for your time.

=Chris

Accelerometer Datasheet 

http://www.st.com/stonline/products/literature/ds/15094.htm 

[Klepackage]

When I open up the Write Read.vi that is part of the larger sample VI, I notice the number of bytes to read is set to 0.  When I change it to anything other than 0 and run, I receive the error code -301742 in the error out window.  I have no idea how to diagnose this because no text accompanies the error message.

=Chris 

[Jason_D]

Klepackage,

Write Read.VI where did you get this?  As far as the error this forum as some good information that I think may apply.  Does this application work other than trying to read this register?

[Klepackage]

Jason,

I was tinkering around with the General I2C Read.vi.  When you double click on the icon that says 845x I2C (has glasses and a pencil), it opens up a clone of NI-845x I2C Write Read.vi.  That is what I was referring to.

=Chris