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Forum Index : Microcontroller and PC projects : Pico DIN-Rail enclosure & breakout
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Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
I particularly like the options of the 9-35v input and the OLED window. Enclosure Terminal breakout |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 5725 |
TBH I'm rather saddened by the first one. With a bit more thought and a second pcb they could have mounted the Pico above the bottom board, allowing a full set of terminals top and bottom together with some opto-isolators and SSRs. Those cases are often kitted out like that. The Pico could have run across the case, allowing access to the USB from one side. Sorry, I think this was a lost opportunity. The second one is nice, but once again you *need* level shifting (preferably opto-isolation) and 24vDC I/O on any industrial stuff. You just don't run industrial control wiring (which is what DIN rail stuff is all about) at 3.3v. The contacts on relays, switches etc. very often won't reliably make that sort of voltage unless you buy the expensive gold plated option. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Agreed. However, I do have one application where it might just work, even though it's kinda criminal to have so few terminals. USB is accessed from the top which kinda makes sense. I think that the idea is to couple this with Din-rail mounted SSRs for outputs and a Din-rail carrier of optocoupled inputs. |
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Poppy Guru Joined: 25/07/2019 Location: GermanyPosts: 486 |
I assume this issue is about controlling mains and I have no idea what for, please give me some input If I am right. Andre ... such a GURU? | ||||
Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 5725 |
Not necessarily. DIN modules are common in control panels. The control devices might be controlling mains, but it will often be low current to feed contactors that handle the mains side. They may also be switching 24vDC, 24vAC or 110vAC control systems. :) You can switch mains using SSRs, but the little terminals on those modules aren't rated for much current (and often barely make it on voltage rating!). Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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Poppy Guru Joined: 25/07/2019 Location: GermanyPosts: 486 |
Thanks! I only knew them controlling mains before. Andre ... such a GURU? | ||||
Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 3521 |
+1 Option 1 has not enough terminals to put the pi to its potential. For a pic12f508 it is nice. Option 2 is dangerous. The pi with its not very robust io pins at 3.3v mounted on a din rail, next to power electroncs, openly, is asking for trouble. Whatever happens unexpectedly, the pi dies. P.s. Gold plated relais are only marginally more expensive, and I use them a lot. They have a gold flash over robust contacts. This will make them usable in low current applications. But when a high current is applied, the gold vapourizes, and remins is a robust power contact. You only cant go back....;) P.p.s look at Controlino, these guys make a nice control platform for industrial applications, around a simple arduino core. Lots of io. Only the mini, shares pwm and relay outputs, that is not very clever. But the others are very nice. Edited 2021-10-20 19:17 by Volhout PicomiteVGA PETSCII ROBOTS |
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Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 3521 |
Back to option 1.. nice to have a footprint for the pi, and add a switchmode powersupply. But the pi zero is missing some essentialsfor control applications that everybody will add, and that eat lots of the sea of holes: Communication interface (485 or ethernet) Real time clock(essential, unless you are an intelligent IO expander) HID: leds and maybe a switch. These could be the oled option, but then you are talking about the pi(4 euro) adding 26euro(housing) and 25 euro(the oled option). Even at the chineese rtc an communication interfaces its getting close to 70 euro. And then you can add your relays and SSRs. Edit: I just noticed the Controlino prices...that ends the fun. Edited 2021-10-20 19:36 by Volhout PicomiteVGA PETSCII ROBOTS |
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Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
@Volhout I respectfully disagree re: Controllino It's nothing but smoke and mirrors and no different to those who they claim they are going up against. They use "Arduino" to convey the impression of openness and security but in reality, if their PLC dies on a Friday night in a 24/7 production facility, how many hours will that equipment be out of commission, waiting for a new unit to arrive from Austria? Low level signals are a non-issue in industrial equipment. It's all about separation; magnetics and power are typically separated from the low-level stuff. A 100HP Servo drive, under-load, emits a hell of a lot of PWM noise and yet it is commanded via a +/- 10v (high impedance input) motor command. Typically, the command resolution is 12bit. 20v/4096 = (approx) 5mV sensitivity (resolution). I also note that Controllino feature Phoenix-brand relays but they don't show the side of the relay with the printing on it which would be more informative. Could it be because of the "Made in China"? Their I/O is also very limited (I have 80 DIO, BTW) and they don't appear to handle motion control. |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 5725 |
If the Controllino actually housed an Arduino, which could be swapped out, I might be more interested. It's not *really* Arduino compatible unless it does that though, even if it uses the same processor. It's just another single-sourced PLC with proprietary hardware. Phoenix Contact are German. Of course, that doesn't mean that their products are all made there, but that's the same as anyone else. :) The info is written on the top of Phoenix relays IIRC. It is a long time since I last examined one... Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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