R&S RTO6, Руководство пользователя

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Protocol analysis
R&S
®
RTO6
592 User Manual 1801.6687.02 ─ 05
Data position
The data position sets the location in the data field where the instrument looks for the
specified data pattern.
The setting is available in CAN FD option.
The position can be defined if the data field of the frame is longer than 8 bytes - if DLC
≥
9.
"Position" Sets the operator to define an exact position ("Equal") or a data
range.
Use "Any", if the data position is not relevant for the trigger condition.
"Data index
(min)" Defines the number of the first data byte at which the data pattern
may start.
"Data index
(max)" Sets the number of the last byte at which the required data pattern
may start if the "Position" operator is "In range".
Remote command:
TRIGger<m>:CAN:FDATa:DPOPerator
on page 1806
TRIGger<m>:CAN:FDATa:DPOSition
on page 1806
TRIGger<m>:CAN:FDATa:DPTO
on page 1807
Error conditions
If a CAN detects an error, it transmits an error flag at the next bit. The R&S RTO6
detects errors in the message and triggers on these errors even if no CAN node sends
an error flag.
●
CRC error
CAN uses the Cyclic Redundancy Check, which is a complex checksum calculation
method. The transmitter calculates the CRC and sends the result in the CRC
sequence. The receiver calculates the CRC in the same way. A CRC error occurs
when the calculated result differs from the received value in the CRC sequence.
●
Bit stuffing error
The frame segments Start Of Frame, Arbitration Field, Control Field, Data Field
and CRC Sequence are coded by the bit stuffing method. The transmitter automati-
cally inserts a complementary bit into the bit stream when it detects five consecu-
tive bits of identical value in the bit stream to be transmitted. A stuff error occurs
when the 6th consecutive equal bit level in the mentioned fields is detected.
●
Form error
A form error occurs when a fixed-form bit field contains one or more illegal bits.
●
Ack error
An acknowledgement error occurs when the transmitter does not receive an
acknowledgment - a dominant bit during the Ack Slot.
●
Stuff count error
A stuff count error occurs if th received stuff count value does not match the value
calculated from the own stuff bit count. Only relevant for CAN FD signals in ISO
standard.
Remote command:
TRIGger<m>:CAN:CRCerror
on page 1807
TRIGger<m>:CAN:BITSterror
on page 1807
TRIGger<m>:CAN:FORMerror
on page 1807
CAN and CAN FD (option R&S RTO6-K520)