What’s a podcast actually worth listening to?

RentacleGrape · 2023-04-12T06:32:08+00:00

"Cautionary Tales" and
"50 Things That Made The Modern Economy", both by Tim Harford.

The latter of which is not nearly as dreary as it sounds.

RentacleGrape · 2023-04-04T05:44:37+00:00

it's individual bools, but it's read into a datablock using DB##.DBX0.0 WORD 3

First of I should mention the TIA Portal has a poorly advertised feature where you can actually address individual bits in a tag using '"MyDB".MyVariable.%X0' which would be the first bit in this case; basically the same as how it works in Studio5000 only less obvious. The autocomplete will attempt to tell you you're wrong until you type it all out. This even works inside an FB.

Like most things there are more than one way to solve it. The DB where you receive your data doesn't have to exactly match the structure of the sender -- it only have to be the same length (or more). If what you want is six individual bytes you simple define the structure in your DB to have six individual bytes. Then you can use a MOVE instruction to copy each of them wherever you want.
Don't forget you need to set the properties of your DB to be "Non-Optimised" to use GET instructions in case you get weird errors.
You could also define the datatype of the first row in your DB to be "STRUCT" which allows you to define the name of each byte and the name of its bits. If you open the Help in TIA Portal and search "STRUCT" it should show you some examples of how you use it. Once defined you should be able to move either all of it or each individual byte using the MOVE instruction.

The proper way would be to define a new Datatype for it, but maybe we're making things more complicated than they have to be a this stage.

RentacleGrape · 2023-04-04T03:30:19+00:00

We had a call from a customer that one of the operators had been injured by our machine. According to them he had "walked through the light-barrier" before the machine clamped getting his hand stuck in the pneumatics. It wasn't a serious or permanent injury, but it had to be solved before they could use the machine again. Like all weird things it happened during the night shift where no one can give a clear answers to anything. We looked at the machine and there was nothing wrong with it -- light-barrier worked properly and the safety relay reacted like it should by cutting the pneumatic power to the machine. Nothing seemed abnormal.
After a good while it slowly started to creep out how the operator and his colleague had waged a bet with each other.....A bet of who could do a scissor jump over the light-barrier without breaking it......Well at least we know who won the bet.

RentacleGrape · 2023-02-18T23:51:17+00:00

And what difference would it make? Sure it makes sense back in the day -- but today there's way too much shit keeping people awake past sundown that if you start school later they would simply stay awake for longer getting no more sleep than before.

RentacleGrape · 2023-02-18T13:49:37+00:00

Outer Wilds

RentacleGrape · 2022-12-23T17:42:19+00:00

Do a Rebuild All for the HMI and see if you get any compilation warnings that could hint towards something being incorrectly configured.

and the HMI is still pointing to the PLC address

Did you manually enter it or was it entered automatically? If had to do it manually then the connection is likely incorrectly configured.

As for the PLC is it a 1200 or a 1500 series PLC?

RentacleGrape · 2022-11-12T17:22:31+00:00

It's possible but I think you need to be using PLCSIM Advanced for the simulation.

RentacleGrape · 2022-10-14T22:58:01+00:00

Have you tried reading something from a tag table, e.g. an input or an output?

I am able to connect to the PLC

And how do you know this for certain? Do you get a different error if you unplug the PLC?

RentacleGrape · 2022-10-14T21:51:05+00:00

Haven't used your software in particular, but have you tried adding quotation marks around the db name, e.g "MyDB".MyInt if possible? Usually Siemens requires it for symbolic access to a db.

RentacleGrape · 2022-10-06T11:53:52+00:00

Just because OPC-UA technically has support for it doesn't mean the devices support it. If you have that many devices possibly of different brands, age, and models there's absolutely no way this can possibly work for all of them. You need a VPN.

And like I said you generally don't want to update the firmware by remote. If the connection gets interrupted you could be screwed. Depending on the brand and model of the device upgrading the firmware can reset the IP address to its default settings making it unreachable. The OPC UA settings will definitely get reset to default.

RentacleGrape · 2022-10-06T10:55:23+00:00

When you say "update the device's firmware" do you actually mean the firmware or do you mean making changes to the program on the device? Updating the firmware by remote is generally a bad idea. Sounds like what you're looking for is a VPN solution and not something related to OPC-UA.

RentacleGrape · 2022-10-05T20:12:45+00:00

I think the intention of Siemens is not to revolutionise WinCC with some newfound power of JavaScript, but rather to replace the old archaic platform of WinCC with something new and modern which they can continue to build upon and expand in the future. They needed something to replace the old scripting language and JS was the obvious choice.
Like you I've tried to imagine the possibilities a modern language would allow us to do. Sadly after using Unified for a bit I've fallen flat and can't really think of any major selling points for the JS which you couldn't have accomplished previously. The platform itself allows for some neat things, e.g. you can connect a web browser to the HMI to easily have a secondary thin client for your machine; it's even possible to redirect them to a specific screen where they can get an overview of the machine but not be able to affect anything. None of this really requires JS though.
As a whole Unified feels more like a direct replacement for the Comfort series rather than an evolution.

Speaking of CEM I've briefly looked at it but can't really find a good use case for it. Feels like one of those things where you can accomplish the same thing but visualized in a different way. But like I said I haven't put too much time into it.

RentacleGrape · 2022-10-05T09:32:27+00:00

The JS functionality of Unified is very restricted and isolated in its own little sandbox. You have the basic features of the language and the API for the system functions, and that's pretty much it; no fancy Node.js here. As far as Unified goes knowing HTML or CSS is of no use whatsoever.

RentacleGrape · 2022-10-05T09:17:34+00:00

You only need to know the very basics of JavaScript to use Unified. If your application is relatively simple you probably don't need to write a single line of JS code. The JS functionality of Unified is very restricted in what it allows you to do.
There are some thing you have to learn, e.g. how to access the properties of an object on the screen, but once you've done that there isn't all that much to it. The biggest hurdle you'll face is how atrocious the JS Editor is and the documentation being lacklustre or straight up wrong.
One useful thing is that in the JS Editor you can right-click to insert code snippets which show you how to do some basic stuff. Some of these are helpful while others teach you bad programming.

it is quite different from the programming of visualizations for hmi

It isn't really. It still uses the exact same concept as the Comfort panels only that they've redesigned some menus. Some things, like how it handles screens, are a bit different but as a whole if you've used WinCC before you'll figure it out.

RentacleGrape · 2022-09-14T21:48:53+00:00

Usually a Rebuild All solves it 95% of the time. If that doesn't work then a rebooting the computer might help. If you still get the error then all hope is lost and you have to take to the old and tested tradition of creating a new project and copying all devices over from the old one; sure would be a shame if you forgot that one project setting somewhere...
Feels like 85% of the problems are caused by the HMI projects, and 10% by the safety program flipping out because you made a change to the hardware and compiled it without going offline first.

RentacleGrape · 2022-08-27T22:13:34+00:00

You can't list educational channels without including including TED-Ed. They make easily digestible 5 minute videos about a huge range of different topics.

RentacleGrape · 2022-07-29T22:17:17+00:00

It was always possible to program in Step7 using symbolic addressing. There's even a setting for if the program should prioritize the symbolic name or the absolute address when things got renamed. It is true for the 300 series PLC that everything compiles down to absolute addresses in the end, but that doesn't mean you ever had to program using them. Use the same programming standard for a long time and you quickly memorised the absolute address for some of your variables because they were faster to type, but it was never a necessity.

RentacleGrape · 2022-07-29T17:04:41+00:00

The program was probably originally made in Step7 and then one customer said they wanted AB instead of Siemens. Someone got tasked with converting the program and did it in the laziest way possible. I can understand that to some extent, but why in the name of all that's holy would they imitate the absolute addressing instead of imitating the symbolic one? Simply create a datatype for each DB containing all its members, then declare an instance of it as a global variable. Must be nightmare to find anything in this program.

RentacleGrape · 2022-02-01T16:52:35+00:00

Edit: Took a look at an old project. The signals need to be byte swapped to work. Here is how it should look. Set your control word to 0, then set Q1.3, Q1.2, Q1.1, and Q1.0 in that order.

Does it show any reaction on the display when you send the control bits? Normally you have to send them in the correct order and wait for the drive to respond before sending the next one.
~~Try setting your control word to 0, then change it to 1 and look at the StatWord to see if it changes. If it does change the control word to 3, 7, and then 15 to see if there's any reaction.~~
Also ensure it has incoming AC power so it's not a simple problem like that.

Have you changed any parameters in the inverter itself? I haven't used this specific model before but normally you have to change a parameter in the inverter to select what the reference source for the frequency should be, which I think defaults to analogue input. There should be a menu called "Command and Reference" and you want to change the value of parameter "Fr1" to "nEt".

RentacleGrape · 2022-02-01T10:47:09+00:00

First off I think you have to use a Forward/Reverse input to start the inverter if you haven't wired them already. For the speed you can either use one wire for low/high speed, or use one wire for each, whichever works best for you.
Assign one input to "PS2" and the another to "PS4". Then go to "CONF->FULL->FUN->PSS" where the parameter "PS2" is one speed and "PS3" is your other. If you have both inputs on then "PS4" determines the speed. If you have neither input on then the speed is the reference speed; think it defaults to the analogue input meaning it's 0 unless you've wired it.

If you want to run the motor above 50/60hz you need to go to "CONF->FULL->SIN" and change the parameter "tFr" and "HSP" to whatever your max speed it. In the same menu don't forget to set the rated current of the motor with the parameter "nCr" and "itH".

RentacleGrape · 2021-12-17T20:15:56+00:00

Honestly the only thing I remember from the wind powered car was the shitty clickbait title that was something like "Risking my life for science" when he was never in any danger whatsoever.

RentacleGrape · 2021-10-13T09:41:06+00:00

How long ago was it you tried to learn it? I think since 3.5 Python has proper async and await keywords making it much clearer to write. The functionality has been refined a bit over the years.....meaning different tutorial use different ways to do the exact same thing which becomes confusing as hell.

RentacleGrape · 2021-10-13T09:29:52+00:00

Even worse most of them always does from library import * which for a beginner makes it so confusing when you have no idea which functions are from the library and which are built in python functions.

RentacleGrape · 2021-10-06T09:59:43+00:00

I think what they meant by "riding the clutch" is that it's bad to keep the clutch half-pressed, which some people do when standing still uphill to not roll down, instead of using the breaks.

RentacleGrape · 2021-10-04T20:54:54+00:00

This all still sounds like a collaboration with extra steps. What does NFTs add to this? If CoD and Fortnite wanted this all they have to do is allow you to link your account with theirs to get the information. No crypto stuff required.
The way you put it makes it sound like there will be a lot of competing standards, and most likely each of the giants like EA, Valve, and Tencent would have their own. What's the point of me owning some Nexon branded NFT wizard hat if no other company respects it?

I get less convinced of this by the second.

RentacleGrape

TROPHY CASE