Counter/Sensor needed

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Thread Starter

Charlie R Chisholm

Pretty bad when you don't even know how to ask the question....but here goes anyway.
I need to find some sort of interface card that will allow/sense a simple count across up to twelve channels.

Situation: We have from three to twelve processors that are grading items in bins. We need to get a count of each item placed in a particular bin (by grade) In other words, if we have 12 bins being used, there would be a switch or button that would be hit each time an item was placed in the bin and this would register at the pc which switch or button was triggered and allow us to count the items per bin. It is actually a simple problem, but my explaination may not make it seem so.

Any help would be GREATLY appriciated.

BTW, this is to replace scribbled tick lists that are maintained at each bin. More lists are lost than are maintained.
 
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If I am understanding you, sounds like all you are looking for is a digital signal from a sensor into a digital I/O card within your PC? If so you need to ask what kind sensor can detect your part and what is required to put I/O card into your computer. It becomes an exercise of matching your hardware.....computer---->I/O card----->sensor. Then writing software program to tabulate and display your totals.
 
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Robert Scott

I suggest that you use ordinary digital inputs, read by a card such as the DIO-24. Then all you need is the appropriate software to monitor the switches and keep counts in software. Perhaps the only real problem will be to ensure that your monitoring software runs frequently enough to catch all transitions on the switches. What is the shortest expected duration of a bin switch closure? You can write a VxD for Windows 98 or a Kernel Mode Device Driver for Windows 2000/NT/XP that will have better latency than the normal application program timer events.
 
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There are of course many digital input cards on the market that are capable of recognizing the contact closure. Any of these could do the job. How you go about solving this problem depends on your programing capability.

Personally, the quickest and most effective solution for myself would be to use a small PLC that has comunications capability. An example might be the DL-05 and DL-06 from Automation Direct. These devices have software counters, internal power supplies, and a serial port. Use a DDE driver that they have available and you can comunicate directly into a spread sheet. You can put the whole thing together in an afternoon

Regards
Erich Mertz
[email protected]
 
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There are a lot of different ways to approach this, and which one makes sense depends on what kind of talent you have available.

If we posit there is someone (perhaps in your IT department) that can get around in Visual Basic or another high level language then this outline should suffice.

1. Salvage an older computer.
2. Install a digital input board. There a many manufacturers to choose
from (i.e. - Advantech)
3. Connect momentary contact bin count switches.
4. Write enough program to sense the switch change (they'll need to be 'debounced' - a mechanical switch may create several transitions for every 'real' closure) for each channel, and increment that bin's counter
variable.

At some specified time (for instance, at shift change, or, better yet, once per hour ... that'll cut your losses in case the computer goes belly-up) save the values for each bin's counter variables, print them out, etc. They can be saved in any convenient format ... for instance, one possible CSV (comma separated variable) sample is shown below.

Date,Time,Shift,Bin1Count,Bin2Count,Bin3Count, .... BinxCount

You'll probably want to include programming to handle unexpected problems (what to do if computer power is lost, etc.). Programming can be as simple or as complex as you wish so long as there is someone capable of writing it.

Instead of reading direct digital bits another computer-based possibility is to use a 16 input digital-to-serial converter (B&B Electronics sells one), and write the program to read this device's serial output.

In my opinion, it's more important to know exactly how the information will be used, and meshed into the business than the particulars of how information is gathered.

There are also companies (one that comes to mind is Production Process) that specialize in solutions for your application, and can provide turn-key systems. This is a good choice if you don't have computer talent to build from the ground up.

Another possibility is to use discrete counters from Red Lion, Veeder-Root (Danaher), KEP, or other such company. I'm not up on their current offerings, but I'd guess at least one of them have a multiple channel counter that you could adapt to your needs.

Bob
 
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calvin smith

If you can use a 24vdc input you might try a omron
sensor, they have sensors made to detect parts droping through the sensor and you get a pulse out for each.
These could be input to aplc with a operator display for each bin

If you want contact me off list
[email protected]
 
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