cmh

Thanks for the answer!

So as long as I eventually close the Document refnum I don't need to explicitly close the Node refnum?

Hi all,

I'm having problems with a program I've written that hangs after some period of running. The program is fairly simple but it does a lot of xml parsing so to fix the problem I'm looking for things like references that are not closed. I have found one unclosed reference in one of my subVI:s but I can't close it without breaking the program so I look to you for help.

The reference in question is the "Node Out" reference in the NI_XML.lvlib:Get First Matched Node.vi marked in the attached file CloseRef. What I would like to do is really to wire it to the invoke node (and not use the "Refnum in" there) but that does not work because somehow the reference has changed from a document reference to a node reference. If I just close the "Node Out" reference my program doesn't work (I guess it kills the "Refnum in" reference which I need later on).

Any ideas on how I could handle the matter?

Maybe this is not the cause of the program hanging but it's the best candidate I found so far.

Thanks

Martin

Hi,

A colleague of mine also experienced problems when building exe-files of programs containing timed loops. I too would be interested to hear more about this issue.

UPDATE:

Googling revealed that this seems to be a problem with hyperthreading. Disabling hyperthreading might help.

See, e.g. http://forums.ni.com/t5/LabVIEW/LabVIEW-crashes-in-timed-loops/m-p/369195

Regards

Martin

It's been a couple years since I used the 8451, but last time I looked into it you could not easily do it. You might be able to do it if you implemented a whole I2C bit banging library, but that kind of defeats the purpose. I switched over to the Total Phase Aardvark for that very reason. As an added bonus the Aardvark is cheaper and supports 400 kb/s whereas the 8451 only went up to 250(?) kb/s.

The Aardvark indeed seems to suit my purposes much better. Thanks for the info.

Hi all,

I asked the following question on NI:s forum without any response so I hope for better luck here.

I have a question regarding communicating on an i2c bus. I'm new to i2c so please bear with me if I haven't got the concepts right.

I have an i2c bus where I want to remove one device and instead use the NI USB-8451 to simulate the device. Basically when a message appears on the bus with a specific address I should answer it. I think that the communication is set up in a multi-master request-reply fashion in the sense that the bus is not "locked" while a master unit is waiting for a reply. Instead each message consist of an address, the address the message came from, message length, payload data and a checksum. If a device recieves a message it can find out who sent the message and send a reply.

When I read about the USB-8451 it says that it can not act as a slave. Does this mean that I can not do what I want using this module? Can I setup the USB-8451 to monitor the bus for messages with a certain address? If not, is there any other NI module I could use?

Best regards

Martin