Book updated

New module groups added
- Expandable bus controllers
- Expandable bus controller system modules
- X20 hub system
- System modules for the X20 hub system
- X20 redundancy system
- System modules for the X20 redundancy system

Existing module groups updated
- Compact CPU system modules
- Fieldbus CPU system modules
- Bus controller system modules
- Communication in the X20 electronics module
- Bus transmitters
- Bus controller
- Digital input modules
- Digital output modules
- Analog input modules
- Temperature modules
- Other modules
- Counter modules

Accessories added

New: Appendix B "B&R ID codes"