Hello PLCman,
You can achieve this by connecting the same signal to the trendWidth datamembers of all the HyperTrends.
For example, if you are using a Pot1 to scroll (by connecting it to the trendWidth datamember), you would connect the same Pot1 to the all other HyperTrends' trendWidth datamembers.
Hope this helps,
Khalid