PLCs (electrical variety, not the down-the-dustbin carillion variety)

[HughF]

Simple question - what's the best (defined as cheapest entry point and quality software) brand of PLC to get started with? I have oodles of electrical and electronic engineering experience and day job is embedded software, so I know the entry requirements might be steep, but there seems to much choice out there, I'm not sure where to go.

Wago, Siemens, Mitsubishi?

I'm thinking the former 2...

 

[piman]

Hello Hugh,

I've use dthe Allen Bradley (Rockwell) Micrologix PLC's for the small jobs I have done. Obviously cost is proportional to the number of inputs and outputs you need Easy to use and the basic softwre is not too expensive to buy.

Alec

 

[MCKDAVID]

simpler question would be what do you want it to do? if it's just to learn with, stick to the majors as that's where the main development would be, and potential jobs later. we use pretty exclusively Allen Bradley and Siemens.

if it's for a specific function, look at what you need and go from there, analogue or digital input outputs etc. You can usually pick them up second hand easily enough, mind you it gets expensive quickly buying cards, cpu's psu's and then the software licences etc.

probably a question for @daleyd, he's a plc / DCS man....

 

[Luke]

For absolute entry level, look at Siemens Logo! It's now got ethernet comms and a number of features that are beyond a 'smart relay'.

For a very capable, but cost effective PLC, look at Siemens S7-1200.

Once you're familiar with S7-1200 and TIA, the concepts (hardware, software, comms, visualisation) and programming environment extend across the Siemens range.

Disclaimer: I pretty much use Siemens hardware exclusively, so that biases my opinion.

 

[HughF]

Just for learning - I do have a glue logic project that I'll be working on that will require modbus/digital IO and a user interface, but I might just build that in node-red on embedded linux

 

[MCKDAVID]

if it's for learning, I'd say stick with the majors, siemens and AB. My thinking would be that just those 2 would cover the majority of the market already. once you've got them sussed, the rest function along the same principles. Knowing how much PLC specialist have cost me (or more my employers) over the years for reworks and designs, it's a decent industry to know. I know the basics and enough to guide a specialist round what we need, but other than that I leave it to the experts. However all the projects we've done in the last 20 years have been either S7 Siemens or Allen Bradley Controllogix based PLC's with associated HMI's. Decent kit for decent sized systems though (FPSO / platform Living Quarters etc)..

 

[Hood]

I use the Koyo DL06 from Automation Direct and find them nice although most guys in the Mach3/4 world have moved over to the Click PLC's again from Automation direct. I think the Click software is free where as the DL06 software is only free for up to 50 rungs or something like that.

Obviously if wanting to use your skills in future industrial work then going with Siemens or Mitsu or whatever would be the better choice as it will be more common but if just for yourself then the above may be worth looking at.

 

[HughF]

I consider it highly unlikely that I'll ever need to find a job as a PLC contractor - i'll have a look at the click stuff.

If I've purchased the device, why should I then have to purchase the software

 

[Robotstar5]

Cubloc are decent entry level combined PLC/HMI to play with, you can use ladder logic or basic to program them, free software too!.

 

[MCKDAVID]

fair enough.

 

[Hood]

I consider it highly unlikely that I'll ever need to find a job as a PLC contractor - i'll have a look at the click stuff.

If I've purchased the device, why should I then have to purchase the software

Think Lamonde Automation are the UK dealers for Automation direct but not dealt with them for years so not sure if they have the Click stuff.

Yes that is my thoughts on software as well but sadly it is not the way most work, often software costs more than the PLC or Servo Drives etc.

 

[HughF]

There's some awesome stuff on AliExpress - I might go nuts and order a HMI touch panel just for fun

 

[WorkshopChris]

Am watching this with interest as i have a couple of projects coming up soon along a similar line.
The Siemens Logo units may be worth a look even i have managed to use them, smc pumatics had a branded version a few years back i used a lot.
Have dabbled with Mitsubishi controllers a few times but Software costs rule this out from what i can see.
Depending on what functions you need there is now a industrial cased version of the arduino with built on relays that might be worth look as well.
I need to get up to speed with this subject as i am still happiest with a big board full to relays and timers, but the hardware is so expensive now compared to a basic controller.

 

[daleyd]

Hi Hugh I saw this thread earlier but I’ve just got in.

Loads of good advice above, if you want to just learn programming for the moment check out codesys which is a free download and runs on a lot of lower end plc hardware. You don’t even need any hardware, it is a simulation mode which runs exactly like a plc and has built in visualisation to play around with.

You can program in 5 languages (function block, flow chart, ladder, structured text and instruction list). It really is excellent and a great way to learn plc programming with little expense. There’s also loads of good tutorials on you tube.

When it comes to biting the bullet and buying hardware then there’s a few more things to consider. I’m on my phone at the moment but I’ll try and stick some more detail down later.

Dale

 

[daleyd]

Oh - the lower end schneider plc’s use a version of codesys and have free software to download (so machine).

If I was doing some basic jobs I’d look at those very carefully, I’ve had a play with the software and though it looks a bit “simplistic” it functions quite well from what I’ve seen.

 

[HughF]

I'm coming at it from a software angle - I've been working with embedded linux for the last 12 months or so and have extensive MCU experience, this PLC stuff just seems a little interesting and worthy of further messing around with.

CodeSys looks interesting, I'll investigate that some more.

 

[daleyd]

https://uk.rs-online.com/mobile/p/plc-cpus/8066859/

 

[HughF]

The backstory behind all this - I'm building a new 9.6kWh LiFePo4 battery pack for my off grid system and I need to build the glue logic between the BMS i'm using (which supports most modern inverter/chargers directly over can) and my old Outback power systems stuff which has a proprietary control protocol - but does have a newly released modbus tcp interface

 

[daleyd]

I think the schneider stuff has native modbus (modicon are now part of schneider, modicon first invented modbus hence the name).

 

[daleyd]

Am watching this with interest as i have a couple of projects coming up soon along a similar line.
The Siemens Logo units may be worth a look even i have managed to use them, smc pumatics had a branded version a few years back i used a lot.
Have dabbled with Mitsubishi controllers a few times but Software costs rule this out from what i can see.
Depending on what functions you need there is now a industrial cased version of the arduino with built on relays that might be worth look as well.
I need to get up to speed with this subject as i am still happiest with a big board full to relays and timers, but the hardware is so expensive now compared to a basic controller.

Have a look at the schneider range Chris, for things like replacing timers etc and some basic digital type stuff I think they'd be ideal, esp with the free software.

I've got it on my laptop and had a play around this afternoon (While I should have been doing other stuff, oops...!) and I'm quite impressed. Your limited to ladder logic or Instruction List - it does also have a Sequential Function Chart facility but I've not tried this yet.

Download of software is here...


https://www.schneider-electric.com/en/download/document/SoMachineBasicV1.6/

It too has a simulation feature so you can play without actually buying anything.