The Altium Schematic Editor is useful for detailed circuit drawings and for more high level representations

also, such as block diagrams.

I have made a Schematic library of the common Block Diagram symbols that I use all the time and present it

here as a basis for your block diagram drawings. The blocks have reference designators and comments so

you can make a bill of materials with them if you like, but the blocks, as made have no inherent electrical

connectivity.

Connections between blocks can be simulated with wires or lines.

Version 1.0 of the Library in Altium AD10 format can be downloaded here.

The library is free of charge to use anyway you would like.

A sample Bock Diagram made with the free Library - The Library contains basic symbols and Blocks plus

Instruments so that it is useful in sketching out circuit functionality and test systems. It can be the used as is

or built on to include the blocks that your particular discipline requires.

also, such as block diagrams.

I have made a Schematic library of the common Block Diagram symbols that I use all the time and present it

here as a basis for your block diagram drawings. The blocks have reference designators and comments so

you can make a bill of materials with them if you like, but the blocks, as made have no inherent electrical

connectivity.

Connections between blocks can be simulated with wires or lines.

Version 1.0 of the Library in Altium AD10 format can be downloaded here.

The library is free of charge to use anyway you would like.

A sample Bock Diagram made with the free Library - The Library contains basic symbols and Blocks plus

Instruments so that it is useful in sketching out circuit functionality and test systems. It can be the used as is

or built on to include the blocks that your particular discipline requires.