20
13
-0
4
48
IUH-F117-V1-*
Appendix
Curve 2 shows the detection range under optimum operating conditions with a
transmission power of 1000 mW ERP.
Curve 3 shows the detection range under optimum operating conditions with a
transmission power of 500 mW ERP.
Passing Speed
The passing speed is the speed at which the tag moves through the detection
range of a read/write head. The passing speed determines the time during which
a tag is located within the detection range and therefore the time available for
transmitting data. The passing speed depends on a number of different factors.
Example:
Write/read head with the enhanced read read-only code EF command
continuously attempts to read a read-only code.
Time taken for the read-only code to be successfully read = 20 ms
Distance from the tag to the read/write head = 1.5 m for a detection range of
±
30
°
.
The ideal distance is
half the max. read distance as per the datasheet.
Therefore:
Distance covered (s) within the detection range: results from two
attempts
s = 2x = 2
· 1.5 m · tan 30° = 1.73 m
Maximum tag speed:
Under industrial operating conditions, a read attempt may need to be repeated.
The time required for this repeat is taken into account when calculating a
maximum speed under real conditions. The maximum speed in this case is
therefore
150 km/h.
Please consult Fuchs for specific data on read and write times, as well as
passing speeds.
tan 30° =
x
1,5 m
v = = 86,5 m/s ≈ 300 km/h
1,73 m
20 ms
max
