Need advice for a factory floor match / no match system



We want to collect data (raw material lot codes) and input them into a PC for a match / no match analysis. We will use a cordless bar code scanner to scan bar coded lot numbers into a PC app for verification.

If the wrong lot number is scanned, (no match condition) we want to turn on a red indicator light and have it emit a loud audible tone. If the scanned number matches the number in the database, then we’ll turn on a green light and won’t emit a tone.

The bar code stuff is easy since it’s what I do. The light is not a problem, I found a two color LED “tower” type that supports either 18 to 30V DC or 21 to 27VAC power.

My questions is this: Since we’ll be using a PC app to control the lights, we’d like to send a string or characters (RS232) to the hardware that will be controlling power to the lights. One string will make the red light come on for x amount of time and another will make the green the light come on.

If any of you have any ideas on what we’ll need to do this, I’d greatly appreciate it.



Hi WiFiGuy,

Welcome to the OptoForums! Sounds like an interesting application. You didn’t mention which Opto 22 hardware/software pieces you have in the mix, but since this is on a PC I’m wondering if you’re using/will use SoftPAC?

Or perhaps you’re using one of our 232 modules like SNAP-SCM-232? Or a 232 port on one of our [URL=“”]hardware-based controllers?

SoftPAC currently supports Ethernet only, but many of our customers use Ethernet-to-232 adapters (and most modern PCs don’t have a 232 port on them anymore so that might be a good option to consider even if you DO happen to have a 232 port on your PC now).

Assuming you have a PAC in the mix somewhere, you’d want to use a Communication Handle in your PAC Control strategy. See the “Communication Commands” section of Chapter 10 “Programming with Commands” in form 1700, the PAC Control Users Guide for more info.

Any additional details you can provide on which Opto 22 hardware/software would help.
Also remember our support, pre-sales support, and training here in Temecula, CA are all FREE.

Hope that helps.


P.S. Opto 22 is coming out with an LED dimmer (you mentioned LED lighting) very soon. Here’s a link to the datasheet: Form 2036 for part LED-SPCV-LV100W.


Here’s what were looking to do. Sorry for not being able to connect this with your products. I have a feeling that your stuff is a lot more advanced than what we’ll end up needing.

Here’s how we see things working:

A bar code get scanned, a PC-based app compares this entry to what it should be. If the two don’t match, the PC sends a character or a string of characters to a mechanical switch / relay that turns a red light on for some defined period of time. For scans that match, a green light is turned on.

I think I’m looking for mechanical relay that can be controlled by sending ASCII characters to it.


Well, that LED dimmer I mentioned in my P.S. might fit the bill since you send it ASCII characters and it controls a low voltage LED light fixture. It’s RS-485 rather than the 232 you mentioned. That way you can have a 485 network, like one dimmer for the green light and one for the red, and maybe some other 485 devices on the same network if you like? Getting warmer?


Ooh I like the dimmer. Don’t suppose the engineering dept is working on a flourescent dimmer by any chance? That would make a nice DALI lighting replacement.
The current project I’m working on requires me to control a DALI lighting system from an Opto S2 and G75 touchscreens. It would have been awesome if I could have used a total Opto solution for this.


Yes that does sound close to what we are looking for. We don’t, however have an RS-485 need though. The PC that will doing the scan verification will have an RS232 port, and it will be very close to the tower light. Cable distance therefore won’t be a factor.

To add other devices to the network, we do hardwired Ethernet, wireless (802.11 a/b/g) or we use a Cisco work group bridge.


We have a 232 to 485 converter (the AC7).
What other devices to you monitor and/or control? Might you at some point have other Opto 22 hardware/software in the mix?