Civil Engineering Reference
In-Depth Information
Table 4
.21
Rules of the CanKingdom glue layer
Rule
Description
1
Start/stop modes. To force a module to stop and go into silent mode
Mandatory
2
Initiate. To establish an exclusive communication between a module and
the configuration tool
Mandatory
3
Assign CAN IDs to receive and transmit data in a module
Mandatory
4
Assign groups. Make a module a member of a group to receive group
commands
-
5
Remove groups. To expel a module from a group
-
6
Trigger setting. To make a module trigger a task on a message or an
event
-
7
Assigning modules to product or producer-specific groups
-
8
Assigning a physical address to a module identified by its serial number
-
9
Change the physical address of a module
-
10
Bit timing register setting
-
11
Inhibit time. To prevent a module from retransmitting a message until a
certain time has elapsed
-
12
Circular time base setup. To create a global clock
-
13
Repetition rate and open window setup. To set up a time-triggered
communication
-
14
Giving common system wide identifications to messages or groups of
messages
-
15
Create CAN messages from local parameters
-
16
Create CAN messages where the data field is extended into the ID field
-
17
Creating bit filter masks
-
18
Creating advanced message filters
-
A full implementation of CK requires roughly 5.5 K flash memory and 100 K
RAM.
4.5.4
CK Vocabulary
In order to make the CK rules and functions unambiguous, it uses a unique vocabu-
lary and specific CK terms are spelt with a capital letter. The description is based on
a simile of a kingdom where the King in his Capital sets the rules for the Kingdom.
The Kingdom has Cities, each of them ruled by a Mayor. The Kingdom is designed
by a Kingdom Founder, i.e. the system designer and Cities by City Founders, i.e.
module designers. Any information exchange between Cities in the Kingdom is
made via a Postal System. The Capital and each City has a Post Office with a Post-
master (a CAN controller) (Fig.
4.32
).
The only way to communicate within a Kingdom is to use Letters (CAN mes-
sages). Each Letter has an Envelope (CAN ID) and a Page (CAN data field). A Page
is built up of 0-8 Lines (bytes in the CAN data field) and a Line can be constructed
of 0-8 Dots (bits in a byte in the CAN data field). Pages are organized in Docu-
