I have a set of CUB5 counters set up on a machine. They are triggered with photo sensors. I am using 12vdc to power everything. I use the current sinking input on the counters.

The problem I am trying to solve is that some of the items we are counting (cooks aprons) have areas where the photo sensor can shine through (neck loop) and trigger the counter more that one time for each item. There is no practical way to avoid this.

I would like to try to find a way to only count the item if it blocks the sensor for over a certain time period (0-2 seconds adjustable). The time can vary slightly as the conveyor is run with an inverter drive and an encoder. The differential on the good and bad counts is, however, still very large.

Here are the specifics:
The sensor to ground readings are as follows. When the sensor is not blocked (seeing the reflector) it is about 10vdc and when it is not seeing the reflector it goes to around .5vdc (that is 1/2) There is a 12vdc power source that is powering the sensor and counter display.

Here are the components I am using.
Counter
http://www.redlion.net/Products/Grou...Docs/01012.pdf
using input a for my signal

Sensor
http://info.bannersalesforce.com/xpe...ure/119223.pdf
using the white wire for my signal (black wire is not used)

Here is how I see what the circuit should do:

sensor reflected
sensor blocked (main part of apron)
start counting
sensor reflected
stop counting
sensor blocked for 1.2 (guess?) seconds
send count pulse
sensor blocked (neck loop of apron)
start counting
sensor reflected
stop counting
sensor blocked for .2 (guess?) seconds
no count pulse sent
repeat for next item

I do have some limited (read very limited) electronic knowledge. If I have a schematic and the part numbers of components, I should have no trouble building it. Please be specific with the components information.

Sorry this is so long. Trying to be very specific so everyone can understand my situation.

Thanks.