Can a controller act like a brain over Modbus tcp/ip? By which I mean, if I understand correctly, using Modbus and a brain, I can read inputs and set outputs. Can I do the same with a controller, even if it’s not running any programs? A dumb controller, basically.
The reason I’m asking is because I’m working on a project where at the moment all I need is simple I/O control over ethernet. But I’m betting a week’s salary that we’re actually going to need a PAC. And this will be learned when I’m already on-site in a foreign country with two days left until turn-on.
Welcome to the OptoForums. I believe the short answer is “yes,” but let me expound on that to make sure we’re understanding each other correctly.
BTW, good job thinking ahead, especially given the foreign country, 2-days thing!
Our PACs all have native Modbus/tcp support (they act as Modbus slaves, straight out of the box), so you can use a Modbus client (I use Modscan32 for testing) to read/write. Super easy.
I’d say it’s a good idea to get a PAC-R (which is the [U][B]not-so-dumb brain[/B][/U] + controller) vs. just a PAC-EB (just the no-so-dumb brain w/no controller) if you have that option. Some people even buy PAC-Rs and shut of the “control engine” if that need a beefier brain.
If you want your PAC to act as a master, then that gets more complicated and would require a controller, but I don’t think that’s what you’re asking, right?
BTW, another reason to go for the PAC-R vs. -EB is if you want to quickly roll your own mobile app, since groov lets you quickly build an interface for your smartphone (or other device with a browser).