WebBrick Data Output (DO) Event.
This event indicates the current state of a digital output.
Type=http://id.webbrick.co.uk/events/webbrick/DO
Source=webbrick/fromNode/DO/
channel number
ipAdr=dotted ip address
udpType=one of G, A, R
phtType=DO
fromNode=webbrick node number
srcChannel=output channel number.
state=0 or 1 for off or on.
