6555 simultaneous generation acquisition

[EdHopkins]

Hi we are trying to get data in and out of a 6555 card to/from our DUT, which is hooked up to the 6555 card via the provided LabView cabling and with the manual VI tool that can drive sample data out the card, the wiring is correct (confirmed on scope).

However, when we run our automated program that is supposed to load our datafiles and send them out, we do not see the signal at all on the same pin that we drove it with the manual VI tool.

The way our hardware guy wired the board up is kind of arbitrary (some channels are inputs, some are outputs, and not in any particular sequence or organization).

As a silly test to start with we have channels DIO0-DIO15 mapped to acquisition, and DIO16 mapped to generation.  There is one HWS file I created that contains the data stream for DIO16, and then we want to record DIO0-DIO15 while DIO16 is sending data out.

However, we do not see data coming out the wire yet.

Two main questions:

1)  What string values should we be passing to niHSDIO_AssignDynamicChannels() to set up the channel assignment like this?

2)  Do we need to padd the channels in the datafile we are sending to niHSDIO_WriteNamedWaveformU32?

I am wondering if perhaps the data we are trying to send out to DIO16 is going out DIO0 or something.

Thanks.

Ed

[James-B · Accepted solution]

Since you are using the Write U32, that means the write VI expects a 32 bit unsigned integer with each bit associated with an output of the 6555.

So to output to line 16, you'd have to pad the integer with 16 bits.  (Basically output hex 0x 0001 0000 corresponding to 1 bit followed by 16 zeros.)

[EdHopkins]

We finally figured it out using the stimulus/response approach where all channels are bidirectional and direction is controlled by whether your data is 0/1 or Z (vs. L/H/X).