luke

This is my situation: I put acquired data on a waveform chart with update mode set to "strip chart" and I want to view old data using the chart scrollbar. The problem is that after I scroll the chart always moves automatically to the last acquired data. How can I solve this? Thanks!

I made more experiments... You are right: it should be not class-related, but I'm still having the error 91 coming out of a shared-variable-read-node outside classes too. There is a thing that I noticed: the first time that I run my program I usually do not have errors. It can be related to the fact that I use shared variables in VIs started by the VIServer method "Run VI" with the "wait until done" option to FALSE? One note: I do not use autodeploy because every time I use the "Run VI" method LV re-deploys the library and it takes a long time. I also tried using autodeploy and I've got the same behaviour, but I have the suspect that this behaviour can be related to deployment. I think that in a couple of days I will pass from :headbang: to

This makes sense! Thank you for the idea! I will try that!

Thank you! That is really helpful!

PLEASE HELP ME!!!!!

HELP!!! I have to run many dynamic (I need polymorphism) VIs simultaneously, but I cannot make them reentrant (labview tells me that this is not supported!). I made an exaple to show that VIs do not run simultaneously: the correct bhaviour is that the execution time of the two parts should be the same, instead one of the two VIs waits the other to complete excution. Someone has suggestions on how to solve the problem? I really need help Luca Download File:post-2982-1158831171.zip

No, I access a shared variable containing a cluster (of strings and integers) from inside a dynamic method. I also noticed that labview always asks for saving that type of VIs when I close the project, even if I neither open that VI!!!! I also tried to store an object in a shared variable, and I had other problems, but I solved them by flattening the object before storing it in the shared variable (not much elegant, but it works). Have you tried to do this?

I have not be able to create a (simple) VI to generate the error, but sometimes I have an error 91 or -1967362020 when I try to read a shared variable from inside a LVOOP class method. I don't think that the bus is in my code because the error 91 description is "The data type of the variant is not compatible with the data type wired to the type input." and I do not use "variant to data", just read from a shared variable. And the error -1967362020 description is "The provided refnum is invalid." and I do not know what it has to do with shared variables. The erros appear just after the shared variable node.

I need to read from shared variables in two modes: with the standard shared variable node and with datasocket VIs (to have the "wait for updated value"). I do not know what will be the order of read modes. Problems begin when I try to read from shared variables previously accessed with datasocket VIs. I made a simple VI to replicate the error: to generate the error start the VI, press "READ WITH SHVAR" button, press "READ WITH DS" button, and press "READ WITH SHVAR" button again. There should be errors "Unable to locate variable in the Shared Variable Engine" corresponding to variables that have been accessed with datasocket VIs. Does anybody have suggestions? Thanks Luca Download File:post-2982-1157729783.zip

NICE! It seems a simpler approach then dqGOOP. I think that such method is OK, but an automatic tool that creates and updates the "reference class" will be fantastic!

:thumbup: :thumbup: :thumbup: I TESTED IT!!! IT HAS BOTH POLYMORPHISM AND OVERRIDING!!! Now we should find the way to pass parameters by reference!!! Does anybody know how to do it?

I read about the new Object-Oriented features in LabVIEW 8.20. It has inheritance, but it also have polymorphism and overriding? Without these it is impossible to implement some design patterns like the "strategy".

I heared about the possibility to use LV controls (such as graphs) in other languages (such as Visual Basic) using ActiveX (without using Measurement Studio) Do anybody know how can I do that? Thanks

There is the possibility to use an interface like this? http://forums.lavausergroup.org/index.php?showtopic=916 I have not found any suggestion Thanks