making block diagrams in control systems

*To*: mathgroup at smc.vnet.net*Subject*: [mg114664] making block diagrams in control systems*From*: sean <sean_incali at yahoo.com>*Date*: Sun, 12 Dec 2010 05:42:44 -0500 (EST)

http://wolfram.com/mathematica/new-in-8/integrated-control-systems-design/connect-two-systems-in-parallel.html Above website has an example of type of block diagrams commonly used in control systems. I was wondering if the new Mathematica 8 has the functionality to produce these block diagrams? (other than to use Graphplot or other unrelated functions.) If so, can someone please point out how I can make them? Thanks in advance for any info. Sean