Is it possible to tristate a line configured to be an output using a 6509?

[racetercel]

I am exploring the possibility of using our existing 6509 cards in an I2C application. To do this I'd like to be able to tristate an indiviual line. Can this be done? I have tried the following call:

DAQmxSetChanAttribute (*handle, channel, DAQmx_DO_Tristate, 1);

This gave me the following error:

NON-FATAL RUN-TIME ERROR: "discrete.c", line 260, col 9, thread id 0x0000091C: Function DAQmxSetChanAttribute: (return value == -200077 [0xfffcf273]). Requested value is not a supported value for this property. Property: DAQmx_DO_Tristate You Have Requested: 1 You Can Select: 0 Channel Name: Dev1/port0/line0 Task Name: 0_0 Status Code: -200077

Thoughts?

[Sean_C.]

Hello,

Thank you for contacting National Instruments.

Currently only the PCI-653X devices support the Tri-State Mode.

Please see the following Knowledge Base for more information.
http://digital.ni.com/public.nsf/websearch/09B559BE292C75DB8625698500640E0A?OpenDocument

I hope this helps,

Sean C.
Applications Engineer
National Instruments

[METAsolns]

Have you succeeded in writing and I2C driver using a 6509 DIO? I would be interested in knowing as I am just about to try this.

[Nick_F1]

Hi Michael,

Thank you for posting on the National Instruments forums.

I cannot speak for racetercel as to how to build a driver for an I2C application, but it is possible to obtain one from here:  Cal-Bay Systems !2C SPI LabVIEW Interface.

[METAsolns]

Nick

Thanks for this. I am looking into this device and the NI 8451. I am actually going to have to do SMBus as well and am asking Cal-Bay and NI about the clock as the SMBus differs in having a clock timeout. I have done I2C in the past how ever the clock wasn't a proper clock but more like a control line to set up the state.

Michael

[nayer]

Hello Micheal,
Look at this document, let me know if this answers your question.
Regards
Nikhil A

[METAsolns]

Nick

I have ordered the NI 8451. I think the Cal Bay device would work as well but the rest of my system is NI and it's ging to a 3rd party so I will keep it simple.