How can i generate buffered handshaked output from one PXI-6534 card & acquire same data through another PXI-6534 card?

[Nirmal_Sharma]

Hi,

I am testing an interface card which acquires 16 bit digital data at every 5 microsecs along with Dvalid pulse. Dvalid signal is high to low edge signal each time indicating the presence of 16-bit data with OFF time 1 microsecs (variable) & ON time of 4 microsecs (variable) making total of 5 microsecond period in all the possible cases. Interface card stores this input data in temporary buffer. It has got sync circuit which has REQuest signal & Acknowledge signal to have 2 way handshaking protocol.

I am using 2 PXI-6534 modules, Ist acting as source of data, IInd acting as data reader.

In Ist PXI-6534 card, I am using Continu
ous handshake output Vi, i have connected CPULL to +5V pin to make it default high. I m fetching a signal of frequency 200KHz (5 microsec period) to REQ1 of this card. ACK1 is connected to Dvalid pin of interface card.

In IInd PXI-6534 card, I have connected REQ1 & ACK1 signals to respective singals of interface card. I am using Continuous Handshake output vi, i have connected CPULL to +5V pin to make it default high. Whenever data comes from the Ist card, interface card generates high to low REQuest signal connected to REQ1, IInd 6534 card acquires data asserting ACK1 signal after acquisition. This cycle repeats.

Now problem is that i m storing the generated & acquired data in 2 binary files & later i am comparing them. Here i observe that i am missing some data in between. What could be the reason? I have tried to set all the signals status in hardware & vi. Still i am not able to match the generated & acquired data. I am attaching both the vi.

Thanx in advance for your help
,

Best Regards,
Nirmal Sharma

[Bob_Preis]

Nirmal,

I have not tried to set up a duplicate system, but I did have an idea for you. Are you using a SH68-68-D1 cable (it's black)?

The SH68-68-D1 is the only cable you should use with your 6534, or any high-speed digital DAQ device for that matter. The D1 cable is optimized for digital and counter boards, while the SH6868, SH68-68-EP, and R6868 cables are not. Due to limitations in wire inductance and cross-sectional area within the other cables, you could potentially lose or corrupt digital data at high speeds.

On a related note, you cannot use the SH68-68-D1 cable with any MIO board. The SH68-68-D1 ONLY works with digital and counter boards.