Connecting Blocks in a Block Diagram
1. Place the mouse cursor over the triangle connection point on the right side of the start node, until the cursor changes shape to a long arrow.
2. Click the triangle connection point on the right side of the start node and then click the first block. The start node is now connected to the first block.
3. Click the triangle connection point on the right side of the first block and then click the second block. The first block is now connected to the second block.
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You can also select RBD > Auto Connect Blocks to automatically connect blocks based on the order in which they were inserted.