Acrosser Technology AIV-HM76V0FL Series, Руководство пользователя, Страница: 85 / 107

8.2. CAN Message Format
// TYPE DEFINITION
typedef char i8;
typedef unsigned char u8;
typedef short i16;
typedef unsigned short u16;
typedef unsigned long u32;
typedef int i32;
struct CanMsg {
u32 id;
u8 id_type;
u8 length;
u8 data[8];
}
To transmit a CAN packet, the programmer has to fill in the fields in the variable of
type CanMsg and pass this CanMsg variable as an argument to invoke the APIs.
The fields in CAN message are described below:
id:
This field holds the ID information of the CAN packet. In a ‘Standard Data
Frame’ CAN packet, the ID field consists of 11 bits of binary digitals. In an
‘Extended Data Frame’ CAN packet, the ID field consists of 29 bits of binary
digitals. That the CAN packet is a ‘Standard Data Frame’ packet or an ‘Extended
Data Frame’ packet is determined by the ‘id_type’ field in the CanMsg variable.
The ‘id’ field in the CanMsg variable is a 32-bit long space. If a CanMsg
variable is configured as a ‘Standard Data Frame’ CAN packet, the bit[0] ~ bit[10]
in the ‘id’ field is the ID of the CAN packet. The bit[11] ~ bit[31] are ignored when
the APIs in the library processing the CanMsg variable.
If a CanMsg variable is configured as an ‘Extended Data Frame’ CAN packet,
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