- Thread starter HughF
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daleyd
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So, got completely sidetracked today and haven’t had chance to get onto pc, ah well!! I think most of the stuff I’m saying below has already been covered...
If I was buying this stuff for a factory production critical environment I think it would be hard to look past one of the big players, taking into account connectivity (profibus, modbus etc what peripherals do you already have/plan on getting?), back up and support from local dealers/system integrators, functionality and what you already have on site in terms of existing hardware and experience. Cost would come into it, but hardware costs wouldn’t be a million miles away from one manufacturer to another at that level.
For less critical applications or home use then cost vs functionality has to be a huge factor.
As well as hardware costs you also have things like the programming software (which has already been mentioned above) plus any hmi you want to add. Often the hmi will also come with their own software packages and licensing which can add considerably to a project, if your using a lower end plc sometimes more than the actual plc hardware.
Some of the newer models of plc have a built in web browser, meaning you can use a pc as a hmi saving considerably on costs that way. (Going back to codesys again, this supports web browser functionality and has inbuilt visualisation).
For a very small project you can sometimes get trial versions of software that run a limited number of steps, though these are usually too limited to do anything other than the most basic of tasks. Mitsubishi I know offer a month trial of their software before you have to buy, I’d assume others do the same.
I’d certainly recommend scouting around and seeing what software is available for free, as this will certainly be a big part of the project cost if your only doing one or two jobs. A big company wouldn’t balk at laying out several thousand for a couple of Rockwell/Siemens licenses because they know their plant will be relying on those for several years - it’d be hard to swallow when you just want to do a bit of stuff at home!!
If I was buying this stuff for a factory production critical environment I think it would be hard to look past one of the big players, taking into account connectivity (profibus, modbus etc what peripherals do you already have/plan on getting?), back up and support from local dealers/system integrators, functionality and what you already have on site in terms of existing hardware and experience. Cost would come into it, but hardware costs wouldn’t be a million miles away from one manufacturer to another at that level.
For less critical applications or home use then cost vs functionality has to be a huge factor.
As well as hardware costs you also have things like the programming software (which has already been mentioned above) plus any hmi you want to add. Often the hmi will also come with their own software packages and licensing which can add considerably to a project, if your using a lower end plc sometimes more than the actual plc hardware.
Some of the newer models of plc have a built in web browser, meaning you can use a pc as a hmi saving considerably on costs that way. (Going back to codesys again, this supports web browser functionality and has inbuilt visualisation).
For a very small project you can sometimes get trial versions of software that run a limited number of steps, though these are usually too limited to do anything other than the most basic of tasks. Mitsubishi I know offer a month trial of their software before you have to buy, I’d assume others do the same.
I’d certainly recommend scouting around and seeing what software is available for free, as this will certainly be a big part of the project cost if your only doing one or two jobs. A big company wouldn’t balk at laying out several thousand for a couple of Rockwell/Siemens licenses because they know their plant will be relying on those for several years - it’d be hard to swallow when you just want to do a bit of stuff at home!!
puffernutter
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Rather than a PLC, could you use a Raspberry Pi and simple interfaces? I have one controlling the railway signals in my back garden! Python is a flexible but simple language.
Cheers
PN
Cheers
PN
HughF
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It's looking more and more likely that I will end up using a Beaglebone black (my preferred embedded Linux board at present - day job stuff etc) along with node-red to glue my bms to my charger. All the power I could wish for, customisable, no software to license/get involved with and a programming style that I'm used to
puffernutter
Puffernutter
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I'd heard of Node-Red. Colleagues at work were talking about it (very positively) as a simple way of creating control routines. I must investigate further!
Cheers
Peter
Cheers
Peter
