So, HE WHO MUST BE OBEYED wants me to dip my toe into the SCADA pool. I know what it is, I know what it does, but I'm not sure how to implement it. I tried a quick google search, but mostly all I'm finding is a bunch of pushy salesmen.
I want to start with something small and simple and CHEAP, of course. I want to be able to take either a 0-10V or 4-20mA signal from a frequency drive output and display it on a computer screen in real time and archive the data for a period of months.
I'd be willing to take some training, so long as it's not a waste of time and money, but where to even start?
So let's break this down into usable chunks:
"I want to be able to take either a 0-10V or 4-20mA signal from a frequency drive output". Lots of choices of where to go with this, but because of the next steps, I'd say use a PLC. You already have RSL500 (and 5000) so to start out small, you can use a ML1100; inexpensive and ready to go with your RSL500.
"... and display it on a computer screen in real time...". This can technically be done by "rolling your own" GUI (Graphical User Interface) IF you are
already very adept at that sort of thing. If not, the learning curve would kill you. So you need a software package. At the very basic level, all you need for this is an "HMI" (Human Machine Interface) software package. In sticking with a Rockwell theme, that would be something like FactoryTalk View. That runs on your PC and will have the necessary tools to create the graphics on a screen for displaying what you want to see, as well as a way to look at the PLC and extrac info from it, using what's called "tags" for the data points you want to watch (or control).
"... and archive the data for a period of months." That becomes a function of the computer. At a very basic level, a good HMI package like FTV will be able to export data to a .csv file that you can then import into something like Excel to create a spreadsheet of the collected data. There are more complex and functional software packages that you can add onto the HMI, called "Historians" that automate that for you, but for one tag on one drive, that becomes overkill.
But what is your long range goal here? "SCADA" (
Supervisory
Control
And
Data
Acquisition) implies, by definition, supervisory and control functionality, meaning someone wants to sit in an office and not only watch what is happening on a plant or system wide basis, but make decision about it, either automatically as a process control function, or semi-automatically where humans make the decisions from afar and they are executed at the local machine. If that's the overall goal of "HWMBO", then you will want to make sure you use something scalable, meaning you are going to start out small, but will want to eventually increase the S and C functionality. So the cheapest things you can get will likely limit your eventual capabilities. Again, since you already have one of the more expensive aspects, the A-B PLC programming software, I'd consider sticking to that path for upgrading. FTV Machine Edition (ME) is a lower cost "entry level" HMI with enough capability to take you fairly far with one system to start out, then it can be expanded into what's called a "Site Edition" (SE) version as you expand.
Lot's of people will argue about this because they are used to and like other products, and frankly few companies survive that make absolute ****, so pretty much anything you use will be pretty good. But again, familiarity is important when starting out and if there is a larger long term growth plan for this, you want to take that into consideration.
