2
Part number 3E1100 R16
July 2010
Power Supply Requirements
Power for the Prox Mifare Series (Teardrop) reader is usually taken from the
incoming supply of the device to which it is connected. That is, from the:
•
Cardax FT Controller 3000-4R
•
Cardax FT Controller 3000
•
Cardax FT GBUS Universal Reader Interface (Cardax FT GBUS URI)
The supply at the reader should be 13.6 Vdc ± 15% (between 11.5 and 15.6
volts) It is recommended that the voltage should be between 12 and 15 volts to
allow for local installation and environmental conditions, to ensure reliable
operation.
The power source for Prox Mifare Series (Teardrop) readers should only be
linear or good quality switched mode power supplies. The performance of the
reader may be affected by a low quality, noisy power supply.
Cabling
The Prox Mifare Series (Teardrop) reader uses the Cardax IV communications
system. The reader cable entry grommet is designed to accept 4 core, 0.2mm
2
(24 AWG) cable. This cable has an outside diameter of 5mm (1/5 inch). A
short tail of this cable is supplied with connector fitted, with each reader.
When using a single cable to carry both power supply and data from the source
to the reader, both the power supply voltage drop and data requirements must
be considered. The cable uses two wires for data and two wires for power
supply.
Power: The conductor size should be sufficient to ensure that the voltage at the
reader terminals is not less that 12 Vdc.
Data: The capacitance between any conductors or any conductors and the
shield should not exceed a total of 24nF for the entire cable. A twisted
pair is recommended for the data circuit.
It is recommended that the distance between the control unit and the reader
should not exceed 200m (600ft).
Choosing a cable
The cable chart below lists cable sizes and the maximum length for connecting
a single Prox Mifare Series (Teardrop) reader to a Controller and power
supply.
Cable type
Maximum distance *
CAT 5
**
40m (130 ft)
4 x 0.2mm
2
(4 x 24 AWG)
40m (130 ft)
4 x 0.5mm
2
(4 x 20 AWG)
100m (330 ft)
4 x 1mm
2
(4 x 18 AWG)
200m (660 ft)
*
These distances apply to unshielded cable. If shielded cable is used, the
distances will be reduced due to the increased capacitance caused by the
shielding.
