SAINT
Keyword 2000 to
01/20/04
Page 7 of 20
4.2Messages IDs
Message IDs are one byte long and have the following general format:
Type (CAN, BEAN, | Command (Cmd=1) | Tx (1) / Rx (0) | Time Stamp (TS) |
ACP,Class 2, IIC, etc) |
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Bits 3 - 7 | bit 2 | bit 1 | bit 0 |
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The upper nibble indicates the type of message. The following types are defined:
∙Gateway (08)
∙Keyword 82 (10h)
∙Keyword 71 (18h)
∙IIC (20h)
∙Keyword 2000 (28h)
∙IDB (30)
∙ACP (38h)
∙E&C (40h)
∙J1708 (48h)
∙CAN (50h)
∙Class2 (60h)
∙Class2 Block (68h)
∙SPI (70h)
∙BEAN1 (90h)
∙BEAN2 (98h)
Bits 3 to 7 identify the specific communication bus (i.e., Class 2, CAN bus, etc.). Bit 2 is used to designate a command or setup message when set to 1. Bit 1 is the transmit or receive bit with 1 designating transmit and 0 designating receive. Bit 0 is used to designate the Time Stamp. In general, report messages from the gateway use the same identifiers as commands to the gateway.
