Possible effects on read range – HID ProxPass Installation Guide User Manual

Page 3

Rev 7/00

Possible effects on read range

Angle(s) of the

tag (mount in vehicle) - General statement: the more surface are of the tag

the reader can see the better the read range will be. Specifics: The tag will be mounted to
the windshield of various vehicles, from sports cars, mini-vans, standard trucks, to
commercial trucks. Each installation will have a different slope and wrap of the
windshield. The degree of slope and wrap will determine the effective read range.
(example1: Corvette, would have extreme slope and extreme wrap, the tag would be
tilted back at least 45 degrees combined with maybe 10 degrees of wrap would provide
less than 50% of the surface area to the reader).(example 2: Commercial truck, would
have no slope and no wrap (basically the tag would be perpendicular to the reader), this is
the worst case scenario).

Height of approach

(in relation to the reader) - Again, the more surface area of the tag the

better the read range. Tag mounts that are 3-4 feet above or below the reader will knock
the read range down 3-4 feet.(example: Commercial truck, assuming a standard reader
height of 3ft. and the tag mount at 6ft., your read range is about 4ft.)

Width of the lane

(in relation to the reader) - Assuming the worst case scenario of the tag

perfectly perpendicular to the reader, if you approach the reader as a vehicle would at a
distance of less that 1ft., your read range is approx. 3ft. If you widen the approach
distance to 7ft the reads are very intermittent. Conclusion, the vehicle approaching the
reader should be in the 3-6ft. range for consistent reads.

Angle of reader

(in relation to the lane - Most installations will have the reader mounted

parallel to the lane. This helps create the perpendicular presentation. I have found that if
the reader is mounted at a 45 degree angle to the lane it ensures the reader will have
better visibility of the tag and eliminates the perpendicular tag instance.

Speed of presentation -

This has the single greatest effect on read range. You must

approach the reader at no greater than 2ft per second for consistent reads.

Slower

will

provide greater read range (

up to 8ft

) and faster will drastically reduce read range

(

Parallel - at 3ft per second, knocks the read range down to 4ft or less.

Perpendicular - at 3ft per second, intermittent reads of less than 2ft).