TClk and acquisition with PXI 6551

[Karsten_E]

Dear All,

I am relatively new to Labview and especially to this forum.

Apparently I do not fully understand the TClk feature, but I need

to use it. My question is about synchronizing with TClk, acquiring data

and hardware error comparision.

My test-setup consists of a PXI chassis, 1042Q, which houses

two 6551 HSDIO data generators.

I want to write something to a scan chain in my device (some PCB

with a few circuits). At some later point in time, I want to read the

content of the scan chain. As this is a scan chain, reading is performed

by writing some more data to the device (I push data in at the front, the

data in the scan chain toggles out at the back).

Altogether I have 32 channels, 24 for driving data and 8 channels for reading

and comparing. The amount of data is more than 1000 samples (in the attached

example I used 512 samples).

My problem is: I want to write the data, wait some time, and then write some more

data for reading and comparing (see above). If I initiate a read operation every

time I write, it is working - but I am not sure which data is compared during

the final hardware error comparision (this is the disabled part in the disable structure in

the attached file).

However, if I skip the first read operation, I receive the error message -1074118579 (also attached).

Could someone help me ? What am I doing wrong ?

Thanks a lot in advance !

Best regards,

Karsten_E

[HoussamK]

Hi

I did encounter an error as you said. It was "Error -1074118579 occurred at niHSDIO Initiate.vi." I found that this was being caused because I needed to pass the reference for both the generation and acquisition parts. If not I would lose the configuration for the acquisition part.

For more information please go to:

Synchronization with a High Speed Digital Input/Output (HSDIO) Board

National Instruments T-Clock Technology for Timing and Synchronization of Modular Instruments