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Why CRC32?
"In testa che avete, Signor di Ceprano?"
-- Rigoletto
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That is part of the Modbus RTU standard. The Modbus ASCII protocol does not require a CRC but apparently they added it for the binary RTU version. Back then, communication was mostly 9600bps and 19600 was considered fast. RTUs were usually separated at far distances so repeaters and modems were frequently used. In the case of the pipeline, the RTUs were separated by about a quarter mile between them so some were miles away.
Today, the vast majority of communication using Modbus is over TCP/IP and no checksums are used - TCP/IP's error handling is relied on.
"They have a consciousness, they have a life, they have a soul! Damn you! Let the rabbits wear glasses! Save our brothers! Can I get an amen?"
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RTU MODBUS standard uses CRC16.
"In testa che avete, Signor di Ceprano?"
-- Rigoletto
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OK.
"They have a consciousness, they have a life, they have a soul! Damn you! Let the rabbits wear glasses! Save our brothers! Can I get an amen?"
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I supervised the CAM group in the early 70's at GTE where we built PABXes. Our group took circuit data from the CAD group and produced the wire wrap data for Gardner-Denver wire wrapping machines. The data was created and stored on a pair of IBM 370 models 158 & 168. It was accessed from three IBM 1800's via 9600 BPS bi-sync links and stored locally on 2311 disk drives using a MRU algorithm. We drove 30 such wiring machines and 10 testing machines from two of these computers with the third as backup and running low priority applications.
We got more productive work done out of 32K mini-computers than most people get out of 32GB machines nowadays. OF course, we didn't have to worry about fonts, font sizes, colors, windows, icons and all the other glitz.
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He went West, reached one end of the flat earth and fell down.
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Interesting read. Haven't heard form him in years now I know why.
Used to like his stuff, but haven't heard anything in a very long time.
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If you ate a clock, would it be time consuming?
"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!
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You got that thought second hand, didn't you.
"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment
"Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst
"I don't drink any more... then again, I don't drink any less." - Mike Mullikins uncle
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yes, twice a day.
CI/CD = Continuous Impediment/Continuous Despair
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You have to chew it minute bits if you expect to swallow it.
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Don't get tic'd off, but how are we supposed to swallow that? Surely, if it would cause and up-set stomach when daylight savings time arrive. Let's not face this question.
Ravings en masse^ |
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"The difference between genius and stupidity is that genius has its limits." - Albert Einstein | "If you are searching for perfection in others, then you seek disappointment. If you seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010 |
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Not if it was a Clockwork Orange...
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
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Did you go back for seconds?
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I just installed it and...
Shell and hotkeys became unresponsive after awhile of using it. Couldn't control alt delete. Had to hit the "Oh Elephant!" Button.
Browser pages becoming unresponsive and I'm on a Ryzen 7 32GB RAM @ 700MBits of pipe.
]
So it might be a networking issue. I've had problems with them hosing my drivers already this year, and it has been awhile since i've seen this but in prior windows when you had hangs deep in the network stack the whole system would crawl even if you didn't think you were doing much networking, mostly because of the timeouts on things like background UPNP and SMB pinging
Real programmers use butterflies
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I have noticed that hotkeys are unresponsive unless I first click the taskbar. Seems like it matters what has the focus.
The difficult we do right away...
...the impossible takes slightly longer.
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I tried clicking on the start menu and it wouldn't open. Ctrl Alt Del and Ctrl Alt Esc didn't even work.
Real programmers use butterflies
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Have you checked your keyboard connection? Wireless? plug in a wired one to test.
- I would love to change the world, but they won’t give me the source code.
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i checked caps lock and my keyboard is lit anyway. Besides, that wouldn't explain the web pages going unresponsive or the shell not responding to clicks.
It wasn't my (< 6 month old) keyboard.
Real programmers use butterflies
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It works on my computer (famous last word).
CI/CD = Continuous Impediment/Continuous Despair
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I've managed to avoid problems with VS updates - having not installed one for years.
Once upon a time it was a nice tight coding environment. And then it wasn't. And more wasn't.
So, tired of wasn't I went to isn't.
Ravings en masse^ |
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"The difference between genius and stupidity is that genius has its limits." - Albert Einstein | "If you are searching for perfection in others, then you seek disappointment. If you seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010 |
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I just have to hit alt-ctrl-del to make the login button appear (instead of it being visible right away after restart by moving the mouse), but apart from that, it works. I have not restarted a second time though.
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The news item posted by Kent today about a new "PriorityQueue" feature in NET 6 [^] triggered an itch i call: "i-could-make-one-of-those."
Since I had never experimented with SortedSet, I decided to use that and see where it took me. And, it took me to an interesting place as i wrestled with how to define a generic wrapper structure ... SortedSet<T> requires a Type with an IComparer implementation.
After muddling around for an hour or so (several mental buffers needed refreshing), i had a working example that i then tested.
And, then i got snagged as i changed a value in a SortedSet element ... a DateTime Property ... and it appeared the Set did not sort as expected.
With growing frustration, I tried different values, and re-tested.
i began to get angry as my cherished image of myself as an expert debugger began to resemble the aging wreck i see in any mirror i am unlucky enough to look into by accident
Finally, it dawned on me: i expected the wrong result ! Yes, the beast was doing what i told it to do.
i think we need a new word for this special kind of bruised-ego chagrin mixed with plummeting self-esteem ... i'll try to think of one, later ... first, I need to go outside and scream some more.
p.s. code on request
«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali
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