PPoll() is similar to the 'traditional' API function ibrpp(). It causes the interface board to perform a parallel poll, and stores the parallel poll byte in the location specified by result. Bits 0 to 7 of the parallel poll byte correspond to the dio lines 1 to 8, with a 1 indicating the corresponding dio line is asserted. The devices on the bus you wish to poll should be configured beforehand with PPollConfig(). The board must be controller-in-charge to perform a parallel poll.