Rohde & Schwarz RTE - Page 565

Protocol analysis
R&S
®
RTE
565User Manual 1326.1032.02 ─ 20
Sets the bit rate of the data phase. The data rate can be equal or higher than the arbi-
tration rate; and it is uniform and fixed for a given CAN FD bus.
To select a data rate from the list of predefined values, tap the button beside the field.
To enter a specific value, open the keypad. The list of predefined values is also availa-
ble in the keypad.
Remote command:
BUS<m>:CAN:FDATa:DBITrate on page 1490
Synchronization: Sample point, Time segments, Jump width
The CAN bus interface uses an asynchronous transmission scheme. The standard
specifies a set of rules to resynchronize the local clock of a CAN node to the message.
The sample point divides the nominal bit period into two distinct time segments. The
length of the time segments is defined in time quanta according to network and node
conditions during CAN development.
For CAN FD signals, you can define the sysnchronization settings separately for the
arbitration phase and data phase.
To specify the bit timing, enter either "Time seg1" and "Time seg2", or directly the
"Sample point". Additionally, set the "Jump width".
"Time seg1,
Time seg2"
Set the number of time quanta before the sample point (Time seg1)
and after the sample point (Time seg2). The "Sample point" percent-
age value is adjusted accordingly.
Time seg1 comprises the segments Synch_seg, Prop_seg, and
Phase_seg1 which are specified in the CAN standard. Time seg2
matches Phase_seg2 from the standard.
The maximum sum of Time seg1 and Time seg2 is 24.
"Sample point"
Sets the position of the sample point within the bit in percent ot the
nominal bit time.
The time quanta values "Time seg1, Time seg2" are adjusted accord-
ingly.
"Jump width"
Time segment1 may be lengthened or time segment2 may be short-
ened due to resynchronization. Resynchronization corrects the phase
error of an edge caused by the drift of the oscillators. The jump width
defines the maximum number of time quanta for phase correction.
The maximum value of the jump width is 4, or Time seg1 - Time seg2
if this difference is lower than 4.
CAN and CAN FD (option R&S RTE-K3/K9)