Park.CTRL

Gang, Hooking up an Automation Direct P2-32TD2P to an AC/DC LED and noticed the LED is always "on" a little bit. When the output is on, the LED is certainly on, but when the output is off the LED is still on by a fractional amount, not much but it's plainly noticeable the room lights are off. The CPU can be in Stop, no matter, power just has to be on. I think this has to do with the card's load disconnected error functionality. +24V and some fraction of amps is always present at the output whether the output is on or off. I talked with automation people at work who noted there is an Allen Bradley system that does the same thing, it caused them a problem, they had to use a relay or etc to make an off output actually be off. Has anyone dealt with this? I'm new to the Productivity software, but there doesn't seem to be a way to just turn it off in the IDE. It seems ridiculous to have to wire up transistors or relays just to have off be off. Thanks for any ideas.

I meant PID code it from scratch. Still pretty new and didn't know about things like "five minute PID" other drag 'n drop functions.

I did look at Her Majesty's Ship AnyBus. Three hundred combos, amazing. So, hypothetically, I can do AS-i for fun and party tricks, with merely this: Automation Direct BRX PLC supporting Ethernet/IP, Modbus & friends Network switch / crossover cable / etc HMS Anybus AS-i to say, Ethernet/IP All too easy? I did call/email A-D's tech support but I think I confused them. PS: I like Ethernet/IP. Saying "Ethernet/IP" is like saying "Highway/Sedan".

I first saw AS-i at a factory this week and am trying to figure out what Allen Bradley modules can interface it. I am not finding anything, does AS-I go under some different name?

I need to get a project going before holiday but I'll be back for this one.

I got denied on a job interview, there might have been a few things but I think not knowing NEC and lack of experience with three phase hurt me. The NEC stuff is for another thread but how do you get experience with three phase? Unless you're in a shop already 3ph can be tricky to find. We talked about it at school in multiple classes but never anything hands on. Yet the descriptions for these entry level jobs all expect you to have a few years in of working with 3ph. It looks like I can make my own three phase from 120VAC with a small VFD. Maybe find some small 3ph motor at the scrap yard, get a new contactor and practice taking measurements/hooking stuff up. I've no problem building a trainer if I get to study up on 3ph and NEC at the same time. Crazy? Any advice?

Gang, I've gotten a job where I'll be around controls a lot and I want to build my own trainer for personal/professional development. My current PLC experience is one semester of study on the A-B SLC500 and some honors work where I connected some sensors and a FANUC six-axis up to an SLC 500. I was ready to go on an A-B Micrologix 1400 but getting RSLogix is becoming a turn off. I can go on a big rip about it but won't. I've since looked at Automation Direct, Unilogic, Velocio, even Siemens. A-D is almost looking too good to be true. Yet they've been around for a while and it seem like people are using it. I'm trying to wind up with a good platform to get two PLC's, one to make a trainer with and one for the Big Side Project. Here's what I want to do: Trainer: A dozen each I/O, just switches lights etc Analog I/O One HMI Big Side Project: Dozens of I/Os Several analog I/Os Several HMIs Bus stuff: CAN, or AS-i, or etc I'm pretty green with the Bus Stuff but from what I gather, with Ethernet/IP you can use gateways like Anybus to connect to about whatever you want. If I was certain A-D could do this I'd probably go with them. Just wondering what people think. Thanks for any advice.

Thanks, like we always say, safety third. Oops, I misunderstood what the jog should do. I added a contact so it will undo start/run condition. http://www.plcfiddle.com/#b2f7d065-d947-11e7-95de-9daabbf027f5

Thanks for the info Ken. This is all for an A-B trainer, might consider Siemens now. I'm surprised A-B can ignore a whole bus like that.

Gcl, I couldn't help it and wrote your jog thing. Let me know what you think. http://www.plcfiddle.com/#0f300ded-d875-11e7-b081-af7f83c5a458 I used to write these really cool e-stops in class but forgot how and erased it from this. Will try again later. Edit: I remembered my e stop trick. http://www.plcfiddle.com/#4c95f601-d8a1-11e7-a29f-b1792967379a I always thought a fun part of these projects was always making sure it would stop. So many students, when they pulled the stop out the motor would just turn on again. Mine would sit there with the lamp on until all the switches were reset.

Hi gcl, I wound up playing with the fiddlePLC a bit late and found the save, thanks. Then I run the output through tinyurl.com :} Not sure what I'm doing for a PLC trainer but I might get out the textbook and start over at page one with FiddlePLC. Give me a while and I'll look at your challenge problem :} I was surprised how much of this had cooked out since the class so I need to re-educate pronto.

High pass filters have a resistor and a capacitor. Low pass filters have a capacitor and a resistor. Anything in particular you want to know?

So here's what I gathered (...from Reddit) but you use an AS-i master that's on IP, and map that to Profibus in your PLC. I'm butchering that but it's what I suspected. Siemens is the best site to see demonstrations of this. If anyone has more info I'm all ears.

Very fun. I added an e-stop & cooling fan, but forgot how to make timers work. I miss programming these things. It'll be great when you can save programs.

I did this, by the way. Or at least got a decent start. Wired up a little VFD, fuses, load bulb, etc and ran a 1/3 HP 3ph motor off of single. The fun part was that the motor is too big and I had to tweak dozens of variables in the VFD just to get it to start/run without overloading, even then it would overload if too above/below %25 load. But there is so much to learn just from the book it came with, I look forward to finding a tiny 3ph motor and doing some more stuff with it.

Managed switches have features like trunking, VLANs, MAC filtering, advanced POE stuff, port mirroring, security stuff and even some routing. If you don't need those things than just get a switch. If you have to plug things into a big network somewhere, find out who supports it ask them what to do.

I'm just getting into this field and when I search I'm looking for "plc", "controls", "automation", "plc program", "wiring", "panel wiring" with a few token variations on those. I read ads with "Engineer" mentioned, but they usually entail more education than I have.

Just checking. Trust me: if I didn't ask first, the SOP would be a PDF of the NEC and people would wonder why I bought a hard copy. And it looks like the DeWalt minis are residential footnotes. So I look forward to the real book.

Sad to hear but this is amazing history of industry. Thanks for this.

Do you guys actually own the ($95) NEC? Dewalt seems to have reference versions on Amazon for $15~.

Gosh I'm jealous of this guy's homework, I can't stop thinking about it. For his HVAC, could/would you do a PID in gates, or would you do bang-bang?

Oh cool, I just built an MP3 player for an art install. I stuck it on a Arduino MEGA with a bunch of lights and buttons. I don't think you need that though. Check this out: https://www.sparkfun.com/products/13720 Copy your files to an SD, you can use a relay to trigger it. Done Except be careful if you're using an external amp, I have some MP3 board around here where they'd skipped the decoupling capacitors and that causes a ground loop.

We had cool assignments in my PLC class but I always wanted to do an HVAC control, this guy is lucky.