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Auto detection of TEDS sensor

Does anyone know of a technique to automatically detect the presence, connection, or disconnection of a TEDS sensor on a NI-9219 modules in a 9014 cRIO / 9111 FPGA?


We are using the Dallas DS2433 chips for TEDS.  In another windows application, we used the DS9097-S09 reader on a COM port, and scan it periodically for the DS2433 presence pulse.  If the pulse remains, continues on with application as normal.  If the pulse goes away, or starts new on another channel, re-acquire TEDS information.  Continue scanning for pulse changes...


With the NI-9219 module, I have not found any other VIs or property nodes which would allow me any mechanism of detecting this presence pulse or any other change in TEDS.  This all stems from the fact that reading TEDS takes 30 seconds or more, and I can't continue with DAQ while the TEDS is being read, so I can't just periodically scan the inputs.


Any ideas are welcome.

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Hi AMP12


As far as I know I do not think that there is a property or method that might be able to recognize if there is something connected or not. If you know the expected values you could validate if there something connected or not by comparing the values.



Esteban R.  

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Not quite sure what you mean?... The expected value of the TEDS sensor or the analog input?  TEDS sensors could be literally thousands, not to mention the point I may previously that the TEDS scan takes minutes to complete, so I can't just compare TEDS values periodically.


The only method I can see working would be the case on a 4-20mA sensor where the current goes from 0 to any value (over some threshold, say 2mA).  Then run a TEDS scan.  Additionally, if the channel has a TEDS sensor plugged it, then current falls below threshold, re-run a TEDS scan once the current again goes above the 2mA threshold.


The only problem I have is my project specifically has 0-5V output transducer, and could potentially use 0-10V or strain gage based transducers.  Still open to input....

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