2-13
IM 701450-51E
CAN Bus Signal Analysis Function
2
Field or Frame Type
You can select the type of CAN Bus signal field or frame to be used as trigger conditions
from the five types listed below. You can use the AND condition to select multiple types
at the same time. However, RTR and Data Field cannot be specified in combination.
• Start of Frame
The trigger activates on the Start of Frame (SOF). The trigger point is set to the end
position of the Start of Frame.
• Identifier
The trigger activates on an Identifier (ID) matching the specified condition. Four types
of IDs can be specified. A trigger is activated on the OR logic of the four types of IDs.
The trigger point is set to the end position of the ID.
• RTR
The trigger activates on a remote frame (RTR is recessive). The trigger point is set to
the end position of the RTR bit.
• Data Field
The trigger activates on a data field matching the specified condition. The trigger
point is set to the end position of the data field.
• Error Frame
The trigger activates on an error frame. The DL7440/DL7480 considers 6 successive
dominant bits(logical value of 0) as an error frame trigger condition. Therefore, a
trigger occurs if 6 successive dominant bits occur in an overload frame. The trigger
point is set to the end position of the 6th dominant bit.
Note
If multiple field and frame types are combined, the trigger point is set to the trigger point of the
type that appeared last in the time sequence.
Field/Frame Formats and Trigger Position
The following figure shows the field and frame formats and trigger position.
• Data Frame
Interframe Space
InterframeSpace or
OverloadFrame
Recessive
Dominant
Data Frame
Start of Frame
(1 bit)
S
D
Arbitration Field
(Std: 12 bits, Ext: 32 bits)
Control Field
(6 bits)
Data Field
(0 to 64 bits)
CRC Field
(CRC Sequence: 15 bits, CRC Delimiter: 1 bit)
ACK Field
(ACK Slot: 1 bit, ACK Delimiter: 1 bit)
End of Frame
(7 bits )
• Remote Frame
Interframe Space
InterframeSpace or
OverloadFrame
Recessive
Dominant
Remote Frame
Start of Frame
(1 bit)
S
Arbitration Field
(Std: 12 bits, Ext: 32 bits)
Control Field
(6 bits)
CRC Field
(CRC Sequence: 15 bits, CRC Delimiter: 1 bit)
ACK Field
(ACK Slot: 1 bit, ACK Delimiter: 1 bit)
End of Frame
(7 bits)
2.4 Setting CAN Bus Signal Acquisition Conditions