Inhaltsverzeichnis
Werbung
Verfügbare Sprachen
Verfügbare Sprachen
BMD 1E_ _-_ _ _ _/_ _ _-NJ5...
Microwave Position Sensor
2
System description (continued)
2.4
Acknowledgement – PGN 0x00E800
The SAE J1939 protocol allows confirmation of a message
using the PGN 0x00E800 (59392
page 11) to be sent. What should be confirmed is not
the correct physical transmission of the CAN message, but
rather correct processing in the receiver.
In addition to a positive Acknowledgment (ACK, message
was able to be processed) a negative Acknowledgment
(NACK, message could not be processed) is possible.
With an ACK Byte 1 of the PGN 0x00E800 (59392
contains the value 0x00 (0
) and for a NACK the value
10
0x01 (1
).
10
The cause for a NACK to be sent by the BMD SAE J1939
could be for example that the required PGN is not available
or the sent PGN contained non-permissible data.
An Acknowledgment is send only for PGNs in
PDU1 format.
Specification of the PGN 0x00E800 (59392
Length of data
8 byte
Data page
0x00 (0
PDU format
0xE8
PDU Specific
0xFF
Standard priority
0x06 (6
PGN
0x00E800 (59392
Source address
BA
Data field
0x00 (0
Byte 1
0x01 (1
Bytes 2...4
0xFF (255
MA which triggered the
Byte 5
ACK / NACK.
PGN which triggered the
Byte 6...8
ACK / NACK.
Tab. 2-7:
Structure of the PGN 0x00E800 – Acknowledgment
www.balluff.com
) (seeTab. 3-1 on
10
)
10
)
10
)
10
)
10
)
10
) = ACK
10
) = NACK
10
)
10
2.5
Start procedure of the BMD SAE J1939
The BMD SAE J1939 performs a self-test right after
power-on and sends an Address Claimed Message (see
Tab. 2-8) to log on to the SAE J1939 network. The
sequence of the logon process is shown in the status
diagram inFig. 2-5 on page 10. The BMD SAE J1939
supports Address Capable and searches for a new
available address in the range 0x7F...0xFD (127...253
its predefined source address is occupied. If no address is
available in this range, the BMD SAE J1939 sends a
Cannot Claim Address Message. The Cannot Claim
Address Message is structured the same as the Address
Claimed Message, but is send by the otherwise non-
permitted source address 0xFE (254
Specification of the PGN 0x00EE00 (60928
Length of data
Data page
PDU format
PDU Specific
Standard priority
PGN
Source address
Data field
Least significant byte of the
Byte 1
Bits 8...1
Identity Number
Byte 2
Bits 8...1
2nd byte of the Identity Number
Bits 8...6
The 3 least significant bits of the
Manufacturer Code
Byte 3
Bits 5...1
The 5 most significant bits of the
Identity Number
Most significant byte of the
Byte 4
Bits 8...1
Manufacturer Code
Bits 8...4
Function Instance
Byte 5
Bits 3...1
ECU Instance
Byte 6
Bits 8...1
Function
Bits 8...2
Vehicle System
Byte 7
Bit 1
Don't care
Bit 8
0x01
Byte 8
Bits 5...7
Industry Group
Bit 4...1
Vehicle System Instance
Tab. 2-8:
Structure of the PGN 0x00EE00 – Address Claimed
Message
) if
10
).
10
)
10
8 byte
0x00 (0
)
10
0xEE (238
)
10
0xFF (255
)
10
0x06 (6
)
10
0x00EE00 (60928
)
10
BA for Address Claimed
Message
0xFE (25410) for Cannot
Claim Address Message
english
9
Werbung
Inhaltsverzeichnis
