Possible error in USB-6211 Digital Out driver, daqmxbase 3.4.0

[Bryan]

We are using two USB-6211s with Labview 2010 and daqmxbase 3.4.0 and have found it to be very reliable (once some threading problems were worked out).  But we now have encountered what appears to be an error in the driver.

We have been using digital output port 1, line 0 on both with great success.  We also have a counter running as a clock generator on port 1 line 1 (ctr 1 output).  However, when I tried to use digital output port 1, line 1 using the "DAQmxbase Write (Digital U8 1 chan 1 samp)" vi from daqmxbase 3.4.0, the port doesn't respond.  It also doesn't respond if I try to access the line that has been successfully used for the clock generator output.

After some debugging, I have found that the vi "DAQmxbase Write USB-621x (Digital 1D U32 NChan 1Samp)" appears to have an error in it.  The "lineMask" and "newValue" inputs to "nNIMIOXS tDigController WritePresentValue" are not consistent.  In particular, the "newValue" input is only nonzero if line 0 is selected.  For any other line this input is 0 irregardless of the value of the data to be written.

I have tried this using both the U8 and U32 versions of the Digital output.

I have attached the VI that we are using to write to the port - and I don't think it can get much simpler.  The sample is set for port 1 line 0 (which works successfully every time), but if I change it to port 1 line 1, it has no effect on line 1.  However, if I have made an error in using this VI I would be thankful for any asisstance in correcting the misconceptions and making this work correctly.

Bryan Peterson

bryan_peterson@byu.edu

[Bryan]

Oops, my mistake.  I spent too much time thinking in terms of traditional DAQ and DAQmx.  And I missed the vital clue - when selecting the instantiation of the VI it includes the words "U8 (port format)" which means that I have to set the correct bit in the data to match the desired line.  That is, unfortunately, not mentioned in any other documentation on that VI.

It actually appears that the best use of this VI to turn on digital lines is to pass it a word of all ones and just select the desired line.  That way you don't have to worry about matching the data to the selected line, which may be changed from a front panel by the user.

Anyway, there is no bug in the VI.