B&B Electronics 1939STB manual Function

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Function

This is used to show where the message came from. Refer to Table 37. If the Nibble 2 is set to 0, then the message is from the J1939 bus. If Nibble 2 is set to 2, it is an internal message (for example, Vendor ID).

Table 38. MC

		Nibble 2				Nibble 1
Bit 7	Bit 6		Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0

MC

This is a byte from the controller. Nibble 2 is the number of data bytes (0-

8)in the message. Nibble 1, Bit 3 is the message direction. Bit 2 should always be set to 1. Bit 1 and 0 are not used.

30	1939STB4600 Manual
	B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100	- Fax 815-433-5104
	B&B Electronics Ltd – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91 792444	– Fax +353 91 792445

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Contents RS-232 to J1939 Converter CE Model 1939STBTable of Contents Introduction SAE Publications1939STB4600 Manual Description Electrical Specification Physical DescriptionCommunication directed to the device Format Control Byte Byte 3 NibbleByte Vendor String Setup Internal FunctionsVendor String Message Received from the SAE-J1939 BusBaud Rate Setup RS-232 Baud ChangeRS-232 Baud Rate Change cont’d Parity Setup Byte 5 UB3Stop Bit Setup Word LengthExternal Commands J1939 FormatMessage Header Setup Valid Codes for ByteMessage Information J1939 Message Information Two Bit Values for Byte 5Byte IntpndTransmit XTD Bit2 DLC DIRSAE-J1939 Control Header J1939 Message Frame1939STB4600 Manual Byte Shown in Table1939STB4600 Manual Byte 1939STB4600 Manual Bytes 9 1939STB4600 Manual DLC Data Length Code DIR Message DirectionData Field ID Byte Reception of DataSAE-J1939 Bus Function Internal Messages Installation Software1939STB4600 Manual Message Transmission sending data to the 1939STB Saving Message Information File LoggingAppendix A. The Extended can / SAE-J1939 Message Frame Arbitration Field Appendix B. Example