The Physical Layer Working Group of the FlexRay Consortium has issued revision B of the “Electrical Physical Layer Specification” and the accompanying application notes, both in version 2.1. The functional changes with respect to revision A are limited to the interface of the bus drivers to the host processor. The behavior of the bus driver components has been adapted to the behavior of standard CAN driver components. Additionally, chapters 8 (bus driver) and 12 (system timing constraints) have been revised to make them easier to understand. Revision B and an errata sheet, in which all changes are listed, can be obtained from the web site of the FlexRay Consortium (www.flexray.com).