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Łukasz

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Everything posted by Łukasz

  1. I'm using LabVIEW python nodes to call a python script, which creates an instance of OPC Server class. def initServer(url): server = Server() server.set_endpoint(url) ... The Server object cannot be serialized to JSON as well as cannot be pickled (TypeError: cannot pickle '_thread.RLock' object), so I can hardly see the way how to transfer Server object to LabVIEW. In that case I managed to store Server as a global variable in python script. This solutions works - I can call functions (ex. start/stop running) that simply use a global Server object. However, this solution is not secure - because if I lost the python session (due to the LabVIEW issue), I have no access to my Server. That leads to the question: Is there any more secure way to handle that?
  2. Thanks for the answers, the dll which wraps those functions is the easiest way to get it working. However, I was simply curious if there is any other possibility. - to clarify a running variable - it's a flag that specifies if the server should continue its process. If you pass false to UA_Server_run, then it will not start. Strange, but works. I haven't found UA_Server_stop function yet.
  3. Hello, I'm trying to move the example of library use from C to LabVIEW. The function is C looks like that: static volatile UA_Boolean running = true; static void stopHandler(int sig) { running = false; } int main(void) { ... UA_StatusCode retval = UA_Server_run(server, &running); ... the code goes to the Server_run function and stops here as long as the variable running is true. In C stopHandler will change that and the program can finish. How we can transfer this functionality to LabVIEW? What should be connected as a second parameter to the CLF node function?
  4. Hi, I wonder if anyone have created an app for customer using the web VI hosted on SystemLink Cloud. I find there is a lot of fun playing with that tool but I am not sure if its ready to offer solutions based on this technology. I tried it to create a Testing Process Dashboard , where the Teststand sends result via tags - it's stable, looks ok but during development I found many gaps in documentation. However it's just a dashboard. I can see many possibilities if the Web VI, LabVIEW app, maybe web service are used together, but its hard to find any industrial project description on NI webpages. Can you share your experience with me?
  5. Hello, I wonder why my CAN Arb. ID is different when I'm using NI MAX Bus monitor (1700E701) and ncReadNetMult.vi (3700E701). The system is working with extended ID.
  6. There is a ASCII COMTRADE file. 20161014_081348_870.zip
  7. Thank you for your response, i already had read Compact Rio Dev Guide and also we will contact NI support. I just want to be well prepared before project starts. I like to collect any tip, which could be usefull at planning state.
  8. Hi, i'am looking for knowladge about project design pattern for control application with more then 1 cRIO controller. My task is to choose architecture, so i like to know which communication way is common use, which designe patterns are good to build main VIs, general good practice etc. The project is a production line with lots of servos, CVS controler with vision algorithm, and desktop application as a SCADA system. At this point, i think is good to use Simple Messaging Library to send communication in system and Current Value Table to sending data. Also i will use "standard" Queued State Machine Design Pattern on each device. I will be gratefull for any source of knowladge about how to program similar systems. Best wishes, Lukas
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