User's Manual

DataReader Installation
3
Hi-G-Tek Ltd. Microelectronics & Asset Tracking Technology
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3.5. Power Supply Requirements
The DataReader supply voltage is chosen according to the
model, either 12V, 24V or 48V.
Power supply wattage: each Reader consumes maximum 1.7W,
so the power should tolerate the number of Readers in the chain
multiplied by each Reader's power consumption.
EXAMPLE: 10 Readers connected in a daisy chain require
10X1.7=17W power supply.
Note that if the power supply is installed in a high temperature
0
area (usually above 40 C), there is a derate in power supply
wattage. (Refer to power supply manual).
For safety reasons, power supply current should be limited to 3A.
Current limitation should be done internally in the power supply, or
externally with a 3A fuse.
In vehicular installation, a 1A fuse must be used.
In outdoor and indoor system, the power supply should be installed
indoor. For outdoor system, approved power supplies are:
For Indoor system, the power supply should be UL1950 approved.
A desktop style with IEC320 inlet is recommended.
When power supply cable ends are connected directly to system cable,
a proper isolation should be made. Using heat shrink tube is
recommended.
3.6. Cable Selection
The cable is used for power supply to Readers in a chain and for
RS-485 serial communication.
For most applications, 3 or 4 pairs of 24AWG shielded cable is
adequate.
The serial communication requires shielded twisted pair cable,
the power supply requires low ohmic resistance of the conductors.