I found awesome map with peculiar func_button, this button triggers "logic_relay", the relay has 5 seconds delay, then outputs some parameters back to the func_button. I would like it to do that without 5 seconds delay, but I cant really edit someone else map, so I wondered if I can do that from lua.
https://preview.redd.it/9ieay2xk84381.png?width=665&format=png&auto=webp&s=965ef997227911e19400b4692dd50ff0e8219002
For example I'm working on a motion-sensitive security camera system
In Tinkercad, the power supply (not the chip) breaks because too much current is passing through.
I have always been curious to know if implementing relay logic with actual relays (not ladder logic) still happens.
Couple days ago my boss was telling me how he started his career troubleshooting these kind of circuits in 70s and I thought that there might be some of these circuits out there.
Can you share your experience with relay logic if have any? I’m really curious to hear your stories
I'm a software developer moving into electromechanics, as such, all of my perceptions on this topic may be totally wrong.
so the thing is, I have been exposed to PLCs and relay logic recently.
As a software developer, the whole thing feels bend over backwards, the first time I heard of a PLC in my mind it was a "bigger Arduino with more capabilities, I have played with that, this should be nice!", but then I get this ladder logic madness of 4 columns and 150 rows of..just....why?? it just feels like 50 years behind of every piece of technology I have ever worked in.
anyways, is relay logic still a thing in the industry? I mean, do people still design stuff using physical relays instead of coding the logic in a small IC that drives all the relays? why is it still taught? why is it used as an abstaction layer for programming PLCs instead of code? it feels so confusing.
As a note, it's not that I find ladder logic hard, it's pretty easy, but it's so inconvenient and unreadable for anything with any kind of complexity, I feel a named function and written C code would just do the job.
EDIT: Thank you all for your aswers!, I have learned a lot by reading all of you and now I have a differennt view on the topic. Thanks for all the practical anecdotes, for all the diferent points of view. I have grown a bit by reading you.
IO: Shaft input, shaft output on the opposite side, small gear input on the sides (like in the mill and similar blocks).
Behavior: Transmits rotation from both inputs to the output by usual rules, except that if either of the inputs are rotating clockwise, the output will also be rotating clockwise, and the block will be emitting a redstone signal.
Purpose: Distinguishing between clockwise and counter-clockwise directions in a compact and lagless way - among other obvious applications, facilitating the creation of awesome and needlessly complicated gear-based logic computers a-la mechanical calculators.
Reasoning behind this specific IO configuration:
Assuming that direction of rotation represents a ternary logical signal -- 1 for clockwise, 0 for counter-clockwise, and -1 for no signal -- a couple of these blocks front-to-back will form a basic OR gate, with inputs from the sides, output in the front and baseline counter-clockwise rotation input on the back: if at least one of the side inputs is clockwise, the output will be clockwise as well.
Combined with a fact that NOT gates already exist in the game - reversing a direction is as simple as putting two gears together - we would have a functionally complete set of logical gates, with which computational devices of any complexity could be implemented within Create alone. :3
Hi :) I’m working on basic relay logic and can’t seem to figure it out.
Here’s where I’m at so far: https://imgur.com/a/X3A2B09
S1 pushbutton activates red light. S2 pushbutton activates green light. There is a holding contact.
Simple enough, but I need the buttons to break eachother. Meaning that, when -S1 is pushed, -S2 closes, and vica verca.
Any tips? :)
Edit: Solution is placing the interlocks in the holding contact for the switches. https://imgur.com/a/sCJLriG
Here's a quick sketch of what I'm working with here: https://i.imgur.com/xIXjWl9.png
Basically I have four safety interlocks inputs to a quad OR gate: two doors that must be closed, a flow sensor, and a thermostat. All four are configured such that when the system is safe to operate, the respective switches (or in the case of the thermostat, the relay) will be closed, shorting them to ground. A pull-up resistor on these inputs ensures that if the interlocks are not closed, the input goes high. Since this is a quad OR gate, any high input will result in a high output. So far, everything here is good.
The problem is that the CD4072B is only capable of sinking about 1mA of current on the output pin. I'm using an off the shelf relay board that uses an optocoupler to trigger the relay. 5v supply and 1KOhm resistor for the LED inside the optocoupler so I need to sink 5mA.
What would be the best way to go about this?
Basically the title says it all. I'm trying to trigger a 5 volt relay board using a raspberry pi Basically on the a-side I have my 3.3 raspberry pi connections And on the b-side I have my 5-volt connections but this doesn't work I've even checked with a multimeter and I'm getting millivolts so I'm clearly doing something wrong any help would be greatly appreciated
I am reverse engineering the relay logic in and old system now, and its just not working for me. To make it happen in my brain I have to copy the circuit into ladder logic.
Asking the question to the guys who are on the upper side of the 50's age wise? How did you design complex relay logic? All I can come up with is a complex truth table, but even then I am not sure how to write it down.
EDIT: Should have stated that I just transfer it all to ladder logic in the preferred PLC and that works for me. But I can stare at a schematic for hours and hours and still not figure out.
So I am using the raspberry pi 4b and this relay breakout board. The relay board doesn't like the 3.3v from the pi's GPIO's so I have wired one of these Logic level converters to bring the 3.3v up to 5v and when testing everything works as expected and the logic leveler bring the 3.3v up to 5.0v but as soon as I wire that to the relay the 5.0v logic wire coming from the logic leveler drops to 3.0v.
Now I have heard that the logic level converter is a pull-up and the relay would be a pull down but wouldn't the circuity on the breakout board take care of this problem or no?
We had one station that was using the classic electro-mechanical relay logic, and mechanical timers of some sort. No one knew how it really worked. There was a group of engineers that tried to push for a proper reverse engineering so they could port to a PLC, half a decade ago. That got shut down.
We only realized some of the electrical wiring diagrams were missing or extremely degraded after a recent electrical fire burned up a good chunk of the relay logic controls.
While I'm not involved with the mess (yet), from what I've heard, an industrial controls vendor was contacted to see if they could rebuild the relay logic instead of trying to replace it with a PLC, and they noped out of that.
I wish I could post some pictures, but the company has a hard no-camera policy on company grounds.
I'm going to assume that we're going to need to program and wire a new PLC setup from a blank slate and incomplete documentation, with the clocks ticking because the downtime was not scheduled at all.
EDIT: The reason why I'm sharing it here is because I have never worked with mechanical relays before, so porting a burned up setup to PLC is not going to be fun.
Using Fast Travel on the PC yields interesting results.
Ditto with "Leaving Cetus" while in Cetus where you land again in Cetus (some instance the game wants you to be) before going back to your Orbiter.
Coding at its finest.
Hello all,
Could anyone explain or link to a detailed explanation of how the author derived the truth tables for the following Ladder Logic Diagram. Or am I supposed to just "know" or memorize that the ladder logic diagrams correlates with the truth tables? Thanks!
https://preview.redd.it/c5dew7z003g31.png?width=743&format=png&auto=webp&s=4ac50e60def2247aa8dfe7ad57d9e48ef573df40
https://preview.redd.it/r8g338i103g31.png?width=708&format=png&auto=webp&s=da08b3c6e0af8ef66941456b782366d1112d3bc5
Here are a couple more examples the author asks:
https://preview.redd.it/zsyegu4n03g31.png?width=755&format=png&auto=webp&s=678c0f9aa4d5ca62533e6519bde27bbb6e4511e6
https://preview.redd.it/2sicklyn03g31.png?width=765&format=png&auto=webp&s=ef6daebded241197533af2366c6417e25c17612f
Solutions to the above:
https://preview.redd.it/z99gjc7r03g31.png?width=696&format=png&auto=webp&s=4b145021966ed80268eb209945b6775fe6b66c29
Thanks again.
I'm trying to design a circuit that controls several relay boards and I wanted to check some of my assumptions, get a better handle on the reading of a datasheet, and get a recommendation on connecting LEDs.
Ultimately what I'm trying to get to is controlling a number of 5V relays using a 3.3V microcontroller and have an LED on each relay channel for visual feedback. The relays get turned on by bringing it's appropriate control pin to ground.
My current approach is using shift registers (specifically I'm looking at NPIC6C596A but I'm not tied to it) to control the relays but I'm still learning and trying to understand parsing datasheets and how things fit together.
First the shift register above is listed as open-drain. I'm pretty sure this is what I want, is there anything else I need to do besides connecting the relay control pin to these outputs and bring them low to activate the relay (this grounds the relay through the pin when it is low right?). I don't think I need a current limiting resistor on it (each relay seems to consume about 17mA at 5V and the datasheet has the outputs rated for 100mA continuous).
Next that level shifter has a supply range specification between 2.3V and 5.5V does it matter whether I power it from my 3.3V or 5V rail? Does the supply voltage have any impact on the voltage needed to control it? Or the voltage it can control? Does it matter they're not the same? The data sheet say HIGH-level input voltage between 3Vcc and 5.5Vcc with a Min of 0.85Vcc. I have no idea what that 0.85Vcc actually means on this data sheet (is it voltage drop on the pin?) If I power it from my 3.3V rail will there be any issues controlling the 5V relays? If I power it from a 5V rail will the 3.3V from the micro be recognized by the input pins?
The last question I have is connecting the LEDs to the outputs as well. Will connecting the cathode of the LED to a pin shared by a relay cause any issues (assuming I don't sink more current than the pin is rated for)? Does it matter if the supply voltage for the LED matches the 5V of the relay?
If you've gotten this far thanks for reading my flood of questions and thanks in advance for any advice anyone has to offer.
Hello everyone! I've been a journeyman electrician for three years working mostly in the oil and gas industry. One area that I'm really weak in is PLC's and relays. Following plans and landing wires in new construction is easy but trouble shooting is beyond me. I'm getting frustrated with it and I want to know if you guys have any tips, YouTube links or slutty tricks I can use to get better. Thank you!
I used this tutorial from Valve for creating my double doors and they do work perfectly but I always get this console-output while closing the doors:
ERROR: logic_relay door_relay1 has been triggered but is awaiting refire. OUTPUTS WILL NOT BE FIRED!!!
It does not really bother me that much but it still does. Is there any easy fix for it that i am missing? "Allow fast retrigger" did not work btw, game crashed while closing. Haven´t found fixes on the internet.
