Information request USB control

Sorry for the title it was the only way i could think to write what i wanted. I am asking the general audience here some questions.

Right now i am developing an application that uses a camera, the camera is attached to a PC, now when certain events occur i want to have the PC give an output signal or maybe signals.

I have been looking at SainSmart, ICStation, Numoto, and they each have a 4 relay module that plugs into USB port. There is probably more options out there than these 3 but these three were the ones i found on amazon.

So I am basically asking if anyone has used such an item? If they didnt use one of the ones listed what ones did they use?

Where did they purchase such item?

How they would rate the item?

What other options are available and are recommended by the PLC community?

Here are the links for the various parties listed above:

http://numato.com/4-channel-usb-relay-module.html

http://www.sainsmart.com/sainsmart-...for-automation-robotics.html#customer-reviews

One of the things is that each of these seems to be overseas since i live in USA. Was hoping to find something a bit more local.

What environment are you developing your application in?

I have no experience with any of the devices you list. I used LabView this year for my university project, one part of it was to detect the colour of objects using a webcam which then output booleans. They do a USB DAQ which could be used, problem is the software gets expensive especially when you then need add on's such as the IMAQ image drivers (wasn't a problem for me as I had an unlimited student license).

You could use a small cheap PLC such as a micrologix 1000 controlled by archie's AdvancedHMI, which is done in a VB.net environment.

In work we use a lot of ADAM modules, not sure if they do a USB module ours are all ethernet.

You could also use a Raspberry PI which has onboard GPIO.

One way I could think of is by using an arduino or mbed. It would be easy to connect these to your usb and send serial commands to engage the outputs.
Why are you wanting to do it this way ?

Well to answer the questions. application in .net my job is systems integration and repair and i work for a direct mailing company. We send items out for various clients such as AAA AARP and others. the problem is of course the economy so of course pay scale for operators and sorters is toward the lower end. And being we do have somewhat of a turn over rate we are trying to automate some of the things such as the sorting, when tray changes do something (this will be one relay out put), when the part read is not in the database (another relay).

So the camera takes a snap shot of the piece as it goes by, decodes the IMB (intelligent mail bar code) send data in string to PC. PC will then compare this to the clients database. If it is a good code and is in the database it return the value of the tray. When the tray ID changes of course that is when the one relay will alter state. or some other device will alter state. If the piece is bad or incorrect it will trigger a different item and will reject the piece.

Hope that is clear. I was thinking of doing something like a mini plc or something and write code that would go directly to the PLC. but was also leaning toward the PC doing the work and just controlling the relays either serially or USB. I guess that is why i was kind of asking to see what others are doing or have done to see what is the best choice recommendations and such.

I've only dabbled in PC based control, but one option might be to use an Ethernet enabled smart relay. It'll probably cost closer to $100 than $25, but it probably comes with more relays integrated as well.

Got it. Since you are able to write the software and only need a couple relays I think you are looking in the right direction. Plc would be overkill.

Don't save any money on the equipment tho.

Perhaps you can look into remote io like wago and control it by modbus? Again, arduino might be an option. There are some modbus libraries around for those too. I have rewritten a couple on my website.

Yes the old adage is correct here, you get what you pay for, so skimping on the stuff would not be a good idea.

However thus far most of the stuff i have been able to find has to come across the sea. Location most time hong kong, china, india, etc..

Was looking for something more local, hopefully USA soil, and mad in USA. I know the made part is slim to none but though i would throw that in just in case.

So any ideas now that all of this has come to light?

Right now i purchased one of the ICStation 4 relay modules and well lets just say I have not been very impressed with it. First was the delivery time, took like 4 weeks, second is the tech support, i plug the device in like the poorly written docs says to do and all the PC does is say USB device not recognized. Their responce so far has been install driver, they sent in replacement driver, still does not work.

I've done my sprinkler with an Arduino and Relay interface, works pretty good.

For actual applications, I would get something more serious.

WAGO is pretty affordable, the remote IO interfaces with loads of different protocols. Not sure on the price tho. http://www.wago.us/products/compone...50753-series/digital-output-modules/overview/

From what you have described, I would lean towards doing it all in a PLC, and then, if you need to, connect the PLC to a PC for database updates etc.
I am a big fan of automationdirects Do-more line, and have been very impressed with it's speed, and ability to interface with my .NET apps.

@boneless - you mentioned you have done things with an Arduino, then you said it might not be industrial enough. Why?

Just wondering because i was actually thinking of using one with the relay board then control the relays via USB and my code.

Only reason i thought about doing it this way is because the two USB relay modules that i have bought to try have both been a dismal failure. Not pleased with the quality.

So thought with all the support for the Arduino why not think about using that. Just your comments have me wondering if i should actually be thinking of using this.

I said that because the Arduino is really a prototyping board. You can put it in an enclosure and make sure all your connections are soldered, it should be fine . Not every company wants to have something like that around tho .

And I agree, those USB units you have, would not fit the industrial category either .