Twelve axle depressed heavy flat car and other non-typical axle configuration can cause AEI software to have problems. Proper AEI tags can help.

Tag applied without required backing will be difficult to read at high speeds as the required back plane acts to improve the performance of the tag antenna.

Cars with horizontal flanges at the base of vertical sides can deflect RF energy and prevent the tag from being read with low profile or low mounted antennas.

Tagged or untagged, this Scale Test Car would cause problems with AEI site logic.

This eight axle tank car does not have an AEI tag and was unidentifiable by the AEI site.

This tag was applied without sufficient clearance at the bottom, the flange welded to the bottom of the car will prevent some antenna arrangements from reading this tag.

The eight axels on this car do not cause as much of a problem as the fact it has two trucks on each end, sophisticated axel pattern recognition and redundant wheel detectors are required in order to properly identify this car.

The scale car in this photo has only two wheels and does not fit any wheel pattern, add to this the car typically operates without waybills and can see why the car gets overlooked or not reported/identified.

Not common, does happen, reading multiple tags on a single car, only back office applications can sort this out by knowing which car should be on the consist.

Multiple truck rail equipment, if not properly tagged can confuse AEI site software especially during low speed passing.