B&B Electronics 1939STB manual DLC Data Length Code, DIR Message Direction

Byte 11

Table 32. J1939 Message Information

Message Information

	B			B			B	B		B		B		B
5				6			7	8		9		10		11
		95			E7		0C	80		00		40			8C
	Table 33. J1939 Message Control
	Message Information
	B			B			B	B		B		B		B
5			6			7		8	9		10		11
95				E7			0C	80	00		40			8C

Byte 11

Byte 11 is not sent to the J1939 bus and is coded as follows:

Table 34. Byte 11

	DLC			DIR	XTD
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0

DLC Data Length Code

Number of bytes 0 to 8 in the data payload.

DIR Message Direction

DIR = 1 transmit. The loaded message is transmitted.

DIR = 0 receive. A remote frame with a matching identifier. The message is stored in this message location.

XTD Extended IdentifierXTD = 1 Extended frame

This bit should always be set to one.

XTD = 0 Standard frame

J1939 does not support standard frames.

1939STB4600 Manual 27

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