6534 internal clock is delayed

[mlloyd]

I am using burst handshake I/O protocol to send and receive data via the NI-6534 card. I am trying to communicate with a 3rd party peripheral and have found a problem when trying to RECEIVE data on the 6534 end of things. It seems that the 6534 does not start outputting it's internal clock (PCLK) until some point after REQ and ACK have been set by the peripheral and 6534, respectively. The timing diagrams shown in the user's manual on page 3-6 indicate that PCLK is a free running clock, but in practice, this is not happening.

How can I configure the PCLK line so that it is always on?
If not, is there some fixed amount of time that PCLK delays before beginning to oscillate?

Thank you very much for your help!
Michelle

[mlloyd]

After more evaluation, I am guessing that the PCLK signal, the internal clock to the 6534, does not begin to oscillate until I start running the VI that waits for the handshake signal.

My next question is then can I wait to receive an input on ports 2 and 3 while trying to send an output on ports 0 and 1? That is, can I simultaneously have group 1 and group 2 ports configured differently?

Thanks,
Michelle

[e-Cash-Money]

Hello Michelle,

I believe you are correct in your guess that the internal clock will not appear the PCLK terminal until the VI is running. For burst handshake I/O protocol, PCLK can be configured for an input or an output. PCLK can only output the internal clock after it has been configured to be an output and the VI must be running in order to carry out this configuration.

Yes, you can simultaneously have group 1 (ports 0 and 1) configured for output and group 2 (ports 2 and 3) conifgured for input because there are two groups of timing/handshaking lines to control each group. If you would like to see an example of this and are using LabVIEW, take a look at the following example.

http://venus.ni.com/stage/we/niepd_web_display.display_epd4?p_guid=B45EACE3F06956A4E034080020E74861&p_node=

Hope this helps,
E.Lee

[mlloyd]

Thanks for the info... I would like to try configuring both input and output at the same time. However, I could not access the web link you posted... is this the complete link?

Thanks,
Michelle

[e-Cash-Money]

Hey Michelle,

I'm really sorry about that, here is the proper link:

http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3F06956A4E034080020E74861

Take care,
E.Lee