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Thoric last won the day on August 10 2017

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About Thoric

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  • Birthday July 17

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    LabVIEW 2017
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  1. Hi Igor. In your Readme you state "If input string is 38, 39, 86, 87, 134 or 135 bytes long, the output is incorrect." I tested all string lengths up to 1608 and it failed for 67 strings (various lengths). Do you know why your library doesn't work for certain length input strings, and might it also be wrong for other lengths too? Maybe I can help determine a fix if you have any clues where to look?
  2. I was adding a 'quick' feature to my framework - in retrospect it wasn't the right approach so I've changed my tactic and now I have a better implementation that doesn't require this actor knowing the message origins. I appreciate knowing now though that the addresses are directly identifiable, even if we cannot extract any information about the address from it. Thanks James
  3. James, Is it possible to glean information about the sender of a message? In my Actor I receive a message and it would be useful if I could learn some originator details, namely the Name of the Actor (VI Name perhaps). I wonder if it's possible to learn this info from the Reply to... indicator of a Read Reply Address call? A little bit of background - I want my actor to be smart enough to recognise where a message has come from. It's 'actor agnostic', except for one in particular, and if packets come from that one particular actor I want to perform additional tasks. I can't place additional information into the message itself, so I need this actor to be able to determine the source of the message automagically. Can we do that?
  4. Yeah, playing with this I can see that there's no native way to gracefully handle this. There are tools out there for creating custom popup menus, you can use one of these to generate a dynamic menu that appears beneath the ring control, just as the native control would?
  5. Now I'm intrigued. I want to play to discover, but I might not get to a PC for a while, so apologies if it takes me a little while to reply.
  6. What's wrong with using the Mouse Down? filter event to detect a click?
  7. Interesting - these offerings are significant effort. I was hoping for something simpler, but I wonder perhaps if the use of a 'globalised' notifier is the solution I need. As you state, it's for a limited and clearly defined purpose. I'd be interested to see suggestion 1, (the helper loop, with the main actor template becoming the manager of an internalised worker), provided as another template option from the scripting tools. Thanks for the advice James - professional as always!
  8. James, This may have been answered before, so forgive me if it has. The actor model you use ensures sequential execution of the Event Structure and State Machine. This means the state machine can complete its task(s) without interference from the event structure, because the event structure literally cannot react to any incoming messages until the state machine completes its stack and yields execution. But what if you have a case where this is unhelpful? For example, consider that the state machine is in the middle of a series of state changes, controlling hardware and taking measurements, when an Emergency Stop message comes in. I would want the emergency stop message to be received and reacted upon immediately, with the event structure being able to inform the state machine that it needs to take into account this emergency stop state, change its task list (stack) and instead put hardware in a safe state with immediate effect. Currently I don't see a way to do that without the state machine yielding to the event structure at regular intervals (every 100ms for example), which requires some uncomfortable coding styles. I could, for example, let the state machine yield to the event structure with a status flag set in the shift register that the Timeout Case uses to recognise a need to return to the state machine. This would give the event structure a chance to look at incoming messages and react. But what if a benign message comes in that would normally be held back until after the state machine was finished? Suddenly it gets processed and dealt with too soon. This is why it's important not to yield to the event structure before the state machine is ready to process new requests. Alternatively I somehow use a notification style message within the state machine itself, enabling the possibility of checking an Emergency State notification at regular intervals within the state machine, preventing the need to yield to the event structure. But this notifier would have to be populated from outside the actor, because the event structure is not free to create the notification. This means we now have external source able to directly influence a privately scoped state machine, bypassing the controlling event structure and defeating the primary principle of the actor's stacked structure. Or do we let this fly because we're just using it for emergency notifiers? Your counsel is greatly sought, my friend.
  9. And the problem has returned. No changes. This has to be a race condition. Sadly I no longer have the diagnostic code in there so I have no way to see if the Register had any Observers. I'll reintroduce the code and do some repeat testing (multiple reboots of CompactRIO). Update: I can no longer get it to fail. With or without the code segment above looking at the register, it now always works. And I've literally changed nothing else. ...I wonder if a career shift into crop farming would prove less stressful...
  10. OK, so I think I worked it out. I recover the DVR and run ObsReg to Table.vi and export to file. Unfortunately, introducing this diagnosis code caused the problem to vanish. With this code in place, the issue does not occur. Out of interest, the resultant table contains: All State ObserverSet; 0: EventMessenger (0x79B00000) All Events ObserverSet; 0: EventMessenger (0x79B00000) All Errors -- We have one Event Observer established. Hence the message was received and no problem occurred. For sanity I removed the diagnostic code and recompiled it, and the problem is still gone. Aargh! I haven't changed a single other thing! What's going on!?
  11. Hi James, I tried your probe anyway - unfortunately it causes a deployment error (see image). Without investigating, I'm guessing there's something in there not compatible with RT? I already log the 'states' to a log file, which is how I know if the appropriate states are being fired in each actor. Plus I log all errors to a separate log file. Trying your ideas: 1) Already made that change, just in case 2) Double checked wiring - it's fine. So I took a look at "vi.lib\drjdpowell\Messenging\ObserverRegister\ObsReg Core\ObsReg to Table.vi” which shows how to take an ObsReg Core class and represent it's data in tabular form. How can I use this to investigate the number of Observers on the subactor notifier before I send the reply? I presume this is the motive? Deployment errors when using probes: This is how I record the states to file:
  12. James, the code works in development mode, so using the probe (assuming it works on RT) will show no issues. It's only once built into an executable and deployed that the problem occurs. Once built, I don't see how I can use probes :-(
  13. So, the first thing I tried was a delay between registering for notifications, and sending the first message. This fixed it. So there's a race condition. Basically I can assume that the registration request is performed asynchronously and is not complete before the subactor sends back a message in response to the "Deploy_FPGA" message. James - how can I ensure a regsitration request is complete before the subactor sends a notification?
  14. Errors are captured in the final "" state, so if there was an error it would be sent to the caller (Main) where I log all errors. I don't see any such error. Also, no TCP usage. In the meantime I just quickly created a new project with two actors, one calls the other, and proven: 1. The Self:Initialise state cannot send a notification to the caller - it won't receive it (you knew this, bug 13) 2. Sending a message to the subactor directly after registering for notifications, which gets the subactor to send a reply, does work. But it didn't in my actual project work, only in the test code. So there's either a race condition, timing error, or something else different. I'll look into this more tomorrow.
  15. I tried avoiding the use of Self:Initialise by sending a message to the subactor immediately after registering for notifications. It still didn't work:
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