User Manual

Chapter 6 System Overview
Hi-G-Tek Ltd. Micro electronics & Asset Tracking Technology - 75 -
communications port, depending on the type of RS-485 to RS-232
converter used.
T wo topologies can be used:
 A long daisy chain connection, where all the DataReaders are
connected in one long line.
 A star-type connection, where the DataReaders are split into groups
and each group is connected directly to the converter.
It is recommended that the second alternative be used wherever possible. A
star-type connection provides better tolerance to connection failures. This
alternative is also preferable from the power supply point of view, as only
one power supply for the DataReaders is necessary. The power supply
should be located near the converter. When the line is divided into
segments, the voltage drop along the segments is smaller.
6.5 Systems Segregation
When Hi-G-Tek has designed the system, several security and operational
considerations have been taken into account:
 Similar equipment belonging to one company should not be able to
mess with another company's system either intentionally or
unintentionally.
 Limit unauthorized access between different departments of the same
company. Equipment belonging t o one depart ment of a company
should not be able to interfere with equipment of another department,
either intentionally or unintentionally.
 Service Providers should be able to communicate with their customer's
equipment in order to supply common services to several companies.
This should be done in an authorized an limited manner.