The invention concerns a method in a working machine provided with an implement attachment for the connection of different types of implements. It has a first system (200) for the control and steering of implement connected to the implement attachment. The system (200) has a first CAN bus (201) connected to a plurality of first units (202-204) for the control and steering. The working machine also comprises a second system (300) having a second CAN bus (301) connected to a plurality of second units (302-304) for the control and steering of another set of functions of the working machine. According to the invention, a communication bridge (100) is arranged to transfer information from the first CAN bus (201) to the second CAN bus (301) and vice versa. The communication bridge (100) comprises a process means (108) for selecting information that should be transferred. The process means has a first (101) and a second (102) process module. The first process module (101) steers and monitors the communication bridge (100). The second process module (102) is for the communication between units (202-205) connected to the first CAN bus (201) and units (302-304) connected to the second CAN bus (301). The invention also concerns such a working machine.