Example: Distributed Wireless Control System，可用于无线传感器网络中-This example shows distributed control of a DC-servo using

communication over a wireless network. The example also shows how to

simulate power consumption and how to use the battery block. The model

contains two computer nodes located 20 m apart, each represented by a

TrueTime kernel block. A time-driven sensor/actuator node samples the

process periodically and sends the samples over the network to the

controller node. The control task in this node calculates the control

signal and sends the result back to the sensor/actuator node, where it

is actuated. The wireless communication link is at the same time

subject to a simple power control scheme. Power control tasks running

in both the sensor/actuator node and in the controller node

periodically send out ping messages to the other node to test the

channel transmission. If a reply is received, the channel is assumed

to be good and the transmission power is lowered. If on the other hand

no reply is received, then the transmi