Usb / plc

Anyone know of a small PLC solution. I simply want to control two divices off one USB port, power one on power the second off <-- rotating. Each device is powered by < 3v.

1. I can use a PLC and allow the PLC to switch devices to on off states, simply using the USB (PC software I create) to power on and off the PLC

or

2. Or use some kind of simple switching mechanism connected to the USB

Bottom line is there are two devices that need to alternate on/off on a timed bases that will change from time to time.

Thanks in advance.

Need inexpensive because I plan to use in production. < $30

If you want less than 30 bucks then maybe you can build something using a 555 timer IC (google it for a billion different circuit examples) but otherwise you're looking at more money than that.

You might consider using one of the smart relay products that are on the market. It will be around a hundred bucks.

seems there should be something simple out there, without building. I just need two outputs. No LCD,,, just two outputs to flop. I thought of using a USB to serial converter and using pin outs. Problem is identifying the device, as it is plugged in, and adressing it.

(Can control USB from low power to high power, another problem.)

You don't want to build it but you want it to be less than 30 bucks?
USB IO exists, but its gonna cost you.

http://www.mccdaq.com/products/digital_io_products.aspx

Alaric said:

You don't want to build it but you want it to be less than 30 bucks?
USB IO exists, but its gonna cost you.

http://www.mccdaq.com/products/digital_io_products.aspx

Click to expand...

I think I'm going to buy a smart USB to 9 pin serial, then control pin outs.

Have you googled usb switch?

Here is a link to one I found, might work?

http://www.newegg.com/Product/Produ...96066&cm_re=usb_switch-_-17-196-066-_-Product

Wireguy,

Thanks, I'm checking it out......

Not $30 but less than several hundred here

http://www.sigma-shop.com/category/4/relay-boards.html

Hows that?

In fact, you say you just switch between 2 items, is it always one or the other? Use a single relay unit for 18 Euros! (http://www.sigma-shop.com/product/7/usb-relay-controller-one-channel.html) You could use the n/o contact for one item and the n/c contact for the other item with the supply to the common.

Hey Bernie and Timbo (Leaving Alaric out for the prices!)... Nice finds there, I have no idea what use I'll ever have for them, but those little I/O thingies look like they'd be handy for just foolin' around projects at the house.

On a related note, for home type projects (or, I guess businesses too), where you want to use PC control for things, but not leave a PC running all the time, take a look at the Global Cache devices here. A bit more expensive, but very very flexible for home automation type stuff, and they can take the place of a dedicated PC for scheduling and network interfacing.


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And an aside, since my favorite web-store was mentioned up above there, I have to say...

I Love NewEgg. They are just amazing.

I had a power supply go bad on one of my home PC's, so got on newegg, ordered one, had it the next day, and was thinking... "Hrm... Haven't done a new build in like 18 months...", so yesterday, I ordered everything for a new i7 build (for home)... Case, CPU, Mobo, Video card, the whole nine yards. Just checked this morning, all of it's out on the UPS trucks to be delivered here today! They are actually faster then Amazon or West Marine...

You might be able to kludge together something from an X10 kit? Their sight is a bit much to handle though... it's like they are marketing to teenage boys and horny old men...

I second the endorsement for NewEgg (was I was looking at their daily deals right before coming to PLCS today )

The 30 Dollar Solution!!!!

http://www.usbmicro.com/odn/index.html

Works like a charm!