ShaunR

Can't think of any problems with what you have listed, but there are a couple that I can think of in terms of cons vs queues.. Cannot use them for subpanels (well, you can, but your events won't work). Cannot guarantee execution order (might not be a consideration for you). Cannot easily encapsulate (for the reason you mentioned about typdefs).

Websockets?

Releasing a queue doesn't destroy a queue unless the reference count falls to zero, you wire true to the "Force Destroy" input or all VIs that have references to the queue go out of memory (too many bullets in the gun to shoot yourself in the foot with IMHO). The obtain only returns a reference to a queue, not the queue itself (which can cause memory leaks). This means you have to be very aware of how many "obtains" to "releases" there are in your code and, if you pass the queue ref around to other VIs, ensure that you don't release it too many times and make the reference invalid. Since the VI obtains a new reference and releases it on every call if there is already a reference (which makes it atomic and ensures there is always 1 and only one ref), you only need to get rid of the last reference once you are finished with the queue completely and don't have to worry about matching release to obtains (i.e. it protects you from the ref count inadvertently falling to zero, vis going out of memory and invalidating a queue reference or leakage). The flush is purely so that when you destroy the queue you can see what was left in the queue (if anything). The upside to this is that you can throw the queue VI in any VI without all the wires and only need to destroy it once when you are finished with it (or, as I have used it in the example, to clear the queue).

Why is software so special? It is a tangible deliverable that can be measured and quantified. It's not as if it is like, say, a thought! After consultation to refine the requirements. Yes. I cannot believe you just wrote that. This is reductio ad absurdum argument. What is worse. Is that it is a reductio ad absurdum arguement based on an analogy Let me ask you this though. How much retail software only runs on Windows, or only on Android, or only on Mac? How much retail software written by anyone actually runs on all available operating systems? (environments). You could probably count those that run on more than one on your fingers (LabVIEW being one of them). Large software companies only do anything for one reason and that is to reduce costs and make profit. I would wager very few (if any) companies hire for special roles of public beta tester cordinator, it is usually just an extension of an existing employees role-managers are easy to come by and large companies are full of them. The same goes for IT. So of course they exploit a free resource. They'd be stupid (in business terms) not exploit someones offer to spend time and effort in testing for no free when they would have to spend considerable amount on employing a department to do it.. I don't subscribe to the "software is special and harder than quantum mechanics" school of thinking. I happen to think it is one of the easier disciplines with much less of the "discipline". If you are doing full factorial testing on different PCs then you a) don't have much confidence in your toolchains, b) don't have much confidence in your engineers and c) expecting to produce crap.

Well. "Agile development" is more of a state of mind than a process. In the same respect as TQM, it encompasses many "methods". However. Lets not get bogged down on semantics. I stated I use an iterative method which, simply put, consists of short cycles of requirements, development, test and release-to-quality which runs in parallel with another another iterative cycle (verification, test, release-to-customer/production). There's more to it than that. But that's the meat of it. The release to customer/production are phased releases so whilst all planned features are fully functional and tested. They are not the entire feature set. I will also add that "release-to-customer/production" doesn't necessarily mean that he gets the code. Only that it is available to inspect/test/review at those milestones if they so choose. With this in mind. When I talk about alpha and beta testing. They are the two "tests" in each of these iterative processes. So the customer (who may or may not be internal e.g. another department) gets every opportunity to provide feedback throughout the lifecycle. Just at points where we know it works. We don't rely on them to find bugs for us. Feedback from customers is that they are very happy with the process. The .release-to-customer/production appear on their waterfall charts (they love M$ project ) as milestones so they can easily track progress and have defined visit dates when either we go to them or they come to us. They also have clearly defined and demonstrable features for those dates. With this analogy. The alpha would be a PSU on a breadboard and the beta the first batch PCB that had been soldered a hundred times with no chassis. That's what prototypes in the real world are and that's exactly the same for software. The first production run would be where a customer might get a play. More semantics. When a customer asks you "what can you make for me" he is asking for product. I think actually we agree. I don't propose to just drop it in their lap 6 months after they asked for it. Just that when the job is done. It is done to the extent that he doesn't need to come back to me. Doesn't need to phone, send emails, texts or carrier pigeons except to offer me another project because the last one went so well. Just don't put water in it or you may find it an electrifying experience Not always written. A lot of the time it is just meetings and I have to write the requirements then get them to agree to them. Amazing some of the u-turns people make when they see what they've asked for in black and white. Or, more specifically, what that glib request will cost them

Nope. It's software. It's comparing apples to apples. The expectation of bugs in software is exactly what I was saying about being "trained". There is no excuse for buggy software apart from that not enough time and resources have been spent on eliminating them. That is the reason why there are faster turnarounds in software, because people will accept defective software whereas they will not accept defective hardware. Indeed. However, that can be in parallel with the development cycle where the customers frame of reference is a solid, stable release (rather than a half-arsed attempt at one). If you operate an iterative life-cycle (or Agile as the youngsters call it ) then that feedback is factored in at the appropriate stages. The "Alpha" and "Beta" are not cycles in this case, but stages within the iteration that are prerequisites for release gates. (RFQ, RFP et. al.) Well. If it takes three years to fix something like that, then it's time for a career change! If you know there is a problem, then you can fix it. The problem is that it takes time/money to fix things and the culture that has grown up around software is that if they think they can get away with selling it (and it being accepted); then they will. If it wasn't acceptable they'd just fix it. I've never been an iPhone user (always had androids). However. If the apps are written by any script kiddy with a compiler and given away free, then, basically, you you get what you pay for. The phrase "Good enough" is exactly what I'm talking about. Good enough to get away with? Sky scrapers aren't perfect, but they are "fit for purpose", "obtain an level of quality", "comply with relevant standards", "fulfill the requirements" and don't fall down when you slam a door . The same cannot be said for a lot of software once released, let alone during alpha or beta testing. What's the difference? A balance between what? Between quality and less quality? Software is software. The only difference is how much time a company is willing to spend on it. Please don't get me wrong. I'm not commenting on your products. Just the general software mentality that, at times, makes me despair. I've no idea what that means It's not a "goal".It is a "procedure" and the general plan works in all industries from food production to fighter jets. Why should software be any different? The "goal" is, in fact, that the first time they see it IS the last time they see me (with the exception of the restaurant or bar of course). That means the software works and I can move on to the next project. And I'm saying it doesn't matter what the industry or technology is. It matters very much who the client is and, by extension, what software companies can get away with supplying to the client. Public Alpha and Beta testing programmes (I'll make that discrimination for clarity in comparison with the aforementioned development cycles) are not a "tool" and are peculiar to software and software alone. They exist only to mitigate cost by exploiting free resource. God help us the day we see the "Beta" kettle.

Alpha and beta testing (for me) is internal only. Alpha testing will be feature complete and given to other programmers/engineers to break it on an informal basis. For beta testing, it will be given to test engineers and quality engineers for qualification (RFQ). Sometimes it will also be given to field engineers for demos or troubleshooting clients equipment. Clients will never see the product until it is versioned and released.

Well. I deal with automation machines and if it doesn't work there are penalty clauses. The clients are only interested in what day it will go into production and plan infrastructure, production schedules and throughput based on them being 100% operational on day 1. Deficient software is something desktop users have gotten used to and have been trained to expect. Software is the only discipline where it is expected to be crap when new. Imagine if an architect said "here's your new skyscraper, There's bound to be structural defects, but live in it for a year with a hard-hat and we'll fix anything you find".

How so? They can only put it through use cases if it works. Otherwise they are just trying to find workarounds to get it to work. Alpha = Doesn't work. Beta = Still doesn't work.

....... and here's my offering using queues for command and events for response. (not QSE I know, but we have talked about it-or maybe that was another thread )

It'd end up full of classes then-no thanks...lol. I only release stuff that works and looks clean. I also don't believe in alpha or beta testing (it's just an excuse lazy people/companies use for free resource so they don't have to test it themselves!). I had the intention of doing something with it (I've been using it for over a year now), It was a weekends "playing" that did the job at the time.However, now I'm engrossed with with the SQLite API (only one platform left.....woohooo!). Too many homers what with that, websockets and dispatcher. They are all far more mature than this and consume a considerable amount of my spare time. I probably won't get much time to look at it this side of Xmas (but you never know). But come on Daklu. You could knock up something very similar in a day or two yourself with JCarmodys code if you really wanted it that badly All you need to do is to add a snazzy UI and a database (incidentally, it's not a total coincidence it happens to look very much like a database browser that you may have seen before ). If you want something now, then JCarmodys is your best bet. Why not tinker with that and help him productionize it? With you and JCarmody on the case; I'm sure it will knock the socks off anything I can produce. Otherwise we'll just have to see what Santa brings. Meanwhile. Back at the ranch............

Well. I'm not sure that is such a good idea (I'm gonna call a hector a QSE from now on. People will think I've just mistyped it so it may permeate ). But it is suited to a parser so I could quite easily see a good use for it as an emulator.

Indeed. It is a Queue [based] Sequence Engine. Although I am also guilty of calling it a QSM.

The user cannot change anything at all after the vi is started so it will always execute as expected and the dwell times will always be as they are in the array.. So. You slap my 3 vis into cases. What do you do about getting them to execute in the right order with the right parameters? You mean turn a graphical language into a scripting language? Maybe Luaview is of interest:) You may laugh. But that is exactly what you will find is some of the examples using the JKI QSM on this very board. The answer I was looking for is you cannot stop it (without pressing the Labview stop button) once it has started. But that is the only problem. The point I was trying to make is why break up ordered and sequential things that can be defined by the language so that you have to write a load of code to do the same thing and make it difficult to understand and (as Daklu has pointed out) introduce race bugs?. Admittedly it was a contrived example, but it was to make the point. Daklu an I disagree on many things, but we agree on form over function where the choice is arbitrary. Have you seen the event structure state machine?

The point (I think) that Daklu is trying to make is that some operation ARE atomic and, additionally, sequential - which is implied by the relegation of multiple functions to a single sub-vi. Let's consider a very simple example of an environmental chamber where you want to step it through a temperature profile. You have to set the temperature you want, wait for the chamber to get to a obtain that temperature, wait for it to settle, then save the actual temperature to a file.And you continue like this until you have covered your profile. So we have atomic and sequential operations. Here is the code. Now do this with the QSM thingy without just copying my VIs into cases (don't forget to have cases for open, write and close file as well - after all. It is more "flexible" ) What is the problem with my code that the QSM thingy solves?

Why may I ask? Outside of dynamically loaded VI's, I've never had to consider this. Surely this is a deployment aspect rather than a design consideration.

Where the dequeue loop stops before the message has been processed so that when it starts up again, it processes the stale message. Sometimes 3 (if it uses TCPIP) depending on what you call a "message receive" loop. There is only 1 "receive" loop (i.e. that dequeues messages and acts upon them), but there maybe an event handler (UIs tend to have these by default) and/or a TCPIP handler. Both of these "receive" incoming messages via their respective channels and place them on the receive queue proper. So there are 3 ways that a message may get to be processed in the most complicated case. 1. By placing a message directly on the receive queue (normally only the sequencer will do this). 2. By sending the message to the TCPIP handler (which then places it on the receive queue) 3. By sending the message as an event (which then places it on the receive queue). Although all modules can have all three. Usually No.3 is only used for monitoring purposes if there is no UI (since a UI is event driven-it's there already). It is much more common in non-ui subsystems to have no.s 1 and 2 except for, say, an error handler which (will be 1&3). Since the "receive loops" for TCPIP and events are little more than forwarders (the intention being for within the subsystem only), this means they can be dropped into pretty much any subsytem that doesn't have a UI (well. the TCPIP one can be dropped into anything).

Come up with a way to force LabVIEW to be able to override a class method with a VI that has a different connector pane

Perhaps he means an autosterogram

I'm not a fan of the JKI thingy either, but I would argue that classes are far more prone to this than events (or anything else for that matter). The topology I've now adopted for inter-process comms is a queue for the control, and events for response. This gives a Many-To-One for control (great for controlling via UI and TCPIP) and a One-to-Many for the response. A queue for the response has inherent problems with leftover messages and difficulties with permeating the messages to other processes. However, with Events you can easily add monitors to the response and dynamically register other subsytems to the messages (errors for example).

Because, whilst it is OK for me to use as I know how to get around its foibles, it needs quite a bit of work to make it "prime-time". But the main part (the scan engine) is not dissimilar to JCarmodys. To get something similar, you could just spend a day or so writing it yourself since JCarmody has done most of the work for you .

Don't build an array. Build a cluster.

Right click. Save As

Lol.

Is there any reason you cannot use the TARGET_BITNESS of a conditional disable structure?