How do I synchronize conveyor speeds?

Variable frequency drive opens many options.

A Control Design reader writes: I'm adding a conveyor section to the end of an outfeed conveyor that changes speed due to production demand, and I plan to install a variable frequency drive (VFD). With some products, both conveyors must match speed. What are my options for synchronizing the speed of the new downstream conveyor to the existing conveyor?

Also, depending on the product run, the downstream conveyor will need to run faster to singulate the product, and the distance between product will need to be programmable (+/-0.75 in). What do you recommend? Join the discussion in the comments section below. 

Also read: Drives integrate, gain intelligence