Book updated

New module groups included
- CPUs
- Compact CPUs
- Compact CPUs system modules
- Fieldbus CPUs
- Fieldbus CPUs system modules
- Communication in the X20 IF module
- Communication in the X20 electronics module
- Dgital mixed module
- Other modules

Existing module groups added
- Bus modules
- Terminal blocks
- Bus controller
- Supply modules
- Digital input modules
- Digital output modules
- Analog input modules
- Counter modules

Accessories added