What is the cord that came with my PW used for?
The PC1 cord that is included with all PocketWizard units is primarily for connecting a transmitter to a camera that does not have a hot shoe available. Plug one end into the PC socket found on the lens (leaf shutters) or body (focal plane shutters), and the other to the PocketWizard transmitter. Note: This cord can also be used on the receiving end with certain shoe-mount flashes (Canon 580 EX II, and most Nikon flashes) to connect a PocketWizard receiver to the flash’s PC outlet.