cancel
Showing results for 
Search instead for 
Did you mean: 

Interference problems with fixed readers...

Former Member
0 Kudos

Hello!

Has anyone had any luck dealing with interference problems with fixed readers? We have readers at adjacent dock doors and we were having problems with the tags being read from the reader at the other dock door.

We partially solved the problem by turning down the sensitivity, but we had to turn it down so far that our read rate has dropped to about 75%. That's marginally acceptable and we would like to find a way to bring it back closer to 100%.

This is, in part, due to a current limitation in AII 2.1. I am told it will be fixed in AII 4.0, but we can only assign a document to one reader. So, if a different reader reads the tag, then we are out of luck.

Any suggestions or comments welcome!

Thanks,

John

Accepted Solutions (1)

Accepted Solutions (1)

Former Member
0 Kudos

yeah aii 2.1 has that limitation that only one document can be assigned to a reader at one time... in 4.0 documents can be assigned automatically...

as for the reading issue, I cant speak on that since we only had one dock door with a reader... we did use a motion sensor that only caused a read to be attempted on forward motion and not backward motion(i.e forklift loading a pallet on truck, not unloading from truck)... i could see a scenario like yours happening if every reader installed is just looking for tags to scan and not triggered off motion detection...

Answers (2)

Answers (2)

Former Member
0 Kudos

hi, john Carlson.

As a common way to solve this problem is using filter to filter the interference.

A simple IBM RFID middleware solution is they have edge server and a premise server . The edge server connect to one reader and filter the repeated tag reading, and premise server control saveral edge server and filter the interference tag reading is one of its function.

Regards

Sheng

And AII2.1 is focus on process and I do not know if it will try to enhance its Reader device control part. And I think you'd better do this filter in your software.

Former Member
0 Kudos

Hi Sheng;

The software we have in our device controller does do the filtering (of the repeated tag reading), but it doesn't control the RF overlap we get when the forklift runs through one of the portals. Apparently the motion detectors in the adjacent door can't seem to ignore that fully loaded pallet!

The filtering process, due to our warehouse layout - mostly the product proximity to the door, dictates that once we read a tag, the device controller passes it on to AII and then prevents the tag from ever being passed on again. The only option it appears, until 4.0 changes the way we are allowed to assign documents, is to disable the dock door that is not currently being used. Fortunately, the RFID curve is tall and wide so we are not shipping alot of product.

Thanks to all for your responses!

-John

Former Member
0 Kudos

hi,John Carlson

I think it likely to be a layout problem.

1)try to use aluminium board to shield RF.

2)use line antennas to control the RF range.

just a hint.

Regards

Sheng

Former Member
0 Kudos

we used to have similar problem on our packing line. our boxes goes through 2 reader stations and although we thought it was enough space, some tags were too active that it can be read from other reader. hence created "duplicate" tag error. one set of antennae consisted of antena on both side and on top with conveyer belt going through at the bottom. we called it "tunnel of love". anyway, so what engineers did was created door on each side to shield interference.

in your case, this would not help but I just thought I share...

Former Member
0 Kudos

HI,

There are a few readers and antennas out that can be controlled to limit the range and implement shielding. Depending on your positioning and what you are trying to scan, directional reading (down/up, might help.

Also, there are notes and corrections in sap service notes that realte to the automaitc document assignment. You can modify the process and implement the notes to allow automatic document assignment and vary it, even though its not default implemented. Check for corrections in SP3 fo AIN. I'll chekc to see if we should reference notes from the forum.

Thanks,

Randy