Specifications

4.4. INTERCONNECTIONS

be found in Section 7.

4.4 Interconnections

The RFID and uplink modules will need to communicate with each other.

As they will not be far from each other and data rates are low, but power

consumption and system costs are concerns, a simple wired communication

bus is suitable. There are two primary communication zones:

1. Between the RFID co-ordinator and the two RFID modules; and

2. Between the uplink module and any connected peripherals (such as the

RFID co-ordinator)

These are discussed in further detail in their respective sections.

4.5 Power Supply

The unit should be able to operate from various power sources as mains AC

power is not reliably available across the entire island. Alternative power

sources could include solar, wind and primary cells. The system will have a

battery backup and thus a charging system must be developed.

This proposal recommends a single power supply unit to supply the entire

system, including the uplink module, RFID co-ordinator, RFID readers and

any other peripherals which may be added. Bearing this in mind, it is logical

to co-locate the PSU with the uplink module as this is both a physical and a

logical connection hub for all other devices. A power source will exist at the

uplink module from which all connected peripherals can extract their power

requirements. Details of the power supply design can be found in Section 8.