I have just had my first look at some example VIs using channel wires and I have seen channel wires going from left to right and form right to left in the block diagram. It is my undestanding that best prorgaming practice in LabVIEW always has data wires running from left to right. The VI Analyzer actually checks for the occurance of backward wires. If the new best programing practice is going to allow channel wires to run from right to left then the channel wires should indicate the direction of data flow. My suggestion would be to use a chevron pattern on the channel wire, see attached file.
Duplicate of http://forums.ni.com/t5/LabVIEW-Idea-Exchange/Add-direction-arrows-to-the-depiction-of-channel-wires...