Installation Manual Part 2

Installation manual Reader 63
Modications, misprints and errors excepted
English
6. Operating the reader
6.6.1.1. Transmission power
The cable attenuation is the length-dependent attenuation of the cable at the related frequency:
Pre-setting can be selected under the Current parameter set header. This is done by selecting a parameter set in
the drop-down menu. This parameter is now active and loaded, and the headers are updated. When all the desired
changes have been made, they can be saved. The changes to the settings can be discarded by pressing the Reload
conguration button. The parameter set can be reloaded by pressing the Load factory defaults.
Under the Transmission power header, the parameters of the transmission path can be entered; these include the
transmission power, transmission channel (only ETSI) and spectrum. The applicable standards in the related approval
region are to be observed when setting the transmission power.
Note
To operate the reader in accordance with the related national standards, the antenna gain and the cable
attenuation must be taken into account in the transmission power setting. In no circumstances is it allowed to
exceed the permitted transmission power. Failure to observe this instruction can result in non-compliant operation
of the reader rendering void the unit's type approval.
The radiated power is limited in Europe in accordance with ETSI 302208 to 2 W ERP. In the FCC / IC region, max. 1
W connected RF power applies with an antenna gain of 6 dBi. If the antenna gain is greater than 6 dBi, the RF power
must be reduced accordingly. While the European standard refers to a half-wave dipole, FCC part 15 / RSS 210 refers
to an isotropic radiator.
To set the transmission power, the length-dependent cable attenuation and the antenna gain must be included in
the calculation of the transmission power. An example for the calculation of the transmission power for Europe and
FCC / IC is given in the following.
The following applies to the European approval region:
P
Reader
= P
ERP
+ D
Kabel
– G
HW
P
Reader
...Transmission power of the reader in dBm
P
ERP
......Transmission power based on a half-wave dipole in dBm
D
Kabel
.....Cable attenuation in dB
G
HW
......Antenna gain based on a half-wave dipole
The antenna gain is stated in various different units. These units include dBi and dBic. The units dBi and dBic refer
to an isotropic (spherical) radiator, where dBic refers to a circularly polarised isotropic radiator and dBi to a linearly
polarised isotropic radiator.
In the European approval area, the radiated power must not exceed 2 W ERP. This gure refers to a half-wave dipole.
The relationship shown below exists between an isotropic radiator (dBi) and a half-wave dipole.
D
Kabel
= l*D
dB/m
D
Kabel
....Cable attenuation in dB
l...........Length in m
D
dB/m
.....Attenuation in db/m at frequency