User's Manual

Appendix A System Example
man_905_2.1.doc Page 53
Appendix A SYSTEM EXAMPLE
The following example of a system is a comprehensive guide to using some of the features of the
105 range and design of 105 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 1.5 km (1 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 105U-1 module is installed at the pump station (with address 1) and a 105U-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 105U-1 at the pump station will communicate to it via its serial port.
The following diagram represents the system :-