User manual

Appendix A System Example

man_905-105_2.9 Page 61

Appendix A SYSTEM EXAMPLE

The following example of a system is a comprehensive guide to using some of the features of the range

and design of system.

The example application is a pump station which supplies water from a reservoir to a tank station.

Signals are transferred between the pump station and tank station by radio - the distance between the

two stations is 10 km (6 mile), and the radio path is heavily obstructed by buildings and trees. A

control station is located near the pump station, and there is an existing signal cable between the

control station and the pump station.

A 905U-1 module is installed at the pump station (with address 1) and a 905U-2 module is installed at

the tank station (with address 2). Because the signal cable to the control station does not have enough

cores for all of the signals required, the signal cable is used as a RS485 cable and a 105S-3 module is

installed at the control station (with address 96). As this module has an address greater than 95, the

905U-1 at the pump station will communicate to it via its serial port.

The following diagram represents the system :-

905U-1

905U-2

105U-3

#96