Rainbow Electronics CAN интерфейс - Manual (Page 46)

BOSCH
ROBERT BOSCH GmbH, Postfach 300240, D-7000 Stuttgart 30
Sep. 1991
Part B - page 44
In order to distinguish between Standard Format and Extended Format the reserved bit
r1 in previous CAN specifications version 1.0-1.2 now is denoted as IDE Bit.
IDENTIFIER
IDENTIFIER - Standard Format
The IDENTIFIER’s length is 11 bits and corresponds to the Base ID in Extended
Format. These bits are transmitted in the order from ID-28 to ID-18. The least
significant bit is ID-18. The 7 most significant bits (ID-28 - ID-22) must not be all
’recessive’.
IDENTIFIER - Extended Format
In contrast to the Standard Format the Extended Format consists of 29 bits. The
format comprises two sections:
Base ID with 11 bits and the
Extended ID with 18 bits
11 bit IDENTIFIER
Control
Field
Arbitration Field Data Field
S
O
F
R
T
R
I
D
E
r
0
DLC
Standard Format
11 bit IDENTIFIER
Control
Field Arbitration Field
Data Field
S
O
F
S
R
R
I
D
E
r
1
DLC
Extended Format
r
0
R
T
R
18 bit IDENTIFIER
Data Frame