User manual

56
Serial Bus Analysis
12.8.1 LINBUSConguration
After choosing the BUS type LIN in the BUS menu press
the soft menu key CONFIGURATION. In the menu that
opens you can press the top soft menu key DATA to se-
lect the desired channel via universal knob in the CUR-
SOR/MENU section. The soft menu key POLARITY allows
you to toggle between High and Low; the active function
will be highlighted in blue. An analog or a digital channel
can be connected to LIN-High or LIN-Low. You can select
any version for the LIN standard (version 1x, version 2x,
J2602 or any) via soft menu key VERSION and universal
knob. The option BIT RATE allows you to specify the num-
ber of transmitted bits per second. You can use the uni-
versalknobtochoosefrompredenedstandarddatarates
anduser-deneddatarates(USER).Thehighestpossible
user-deneddatarateis4MBit/s.Youcanentertheuser-
denedvalueviauniversalknobornumericinput(KEYPAD
button).
12.8.2 LIN BUS Triggerung
After the BUSconguration,itwillbepossibletotrigger
on various events. Press the TYPE button in the TRIGGER
section of the control panel and choose the soft menu key
SERIAL BUSES. Then press the SOURCE button in the
TRIGGER section and choose LIN. This will only be availa-
bleifitwasconguredearlier.PresstheFILTERbuttonin
the TRIGGER section of the control panel to list all available
CAN trigger conditions:
❙ START OF FRAME: Triggers on the stop bit of the
synchronizingeld.
❙ WAKE UP: Triggers after a wake-up frame.
❙ ERROR C:Identiesvariouserrorsinaframe.Thismenu
allows you to choose one or several error message types
Fig. 12.21: Layout LIN byte structure
Prior to the BUS conguration it is necessary to set the correct
logic level (threshold). Please refer to chapter 4.5. The default
setting is 500 mV.
Fig.12.22:MenuforthedenitionofaLIN bus
as trigger condition. LIN BUS applies a complex
checksum calculation (Cyclic Redundancy Check). The
transmitter calculates the CRC and transmits the result in
a CRC sequence. The receiver calculates the CRC in the
same manner. A CRC error occurs if the calculated result
deviates from the received CRC sequence. With soft
menu key PARITY triggering occurs on a parity error.
Paritybitsarebit6andbit7oftheidentier.Thecorrect
transferoftheidentierisveried.Withthesoftmenu
key SYNCHRONISATION triggering occurs if the
synchronizingeldindicatesanerror.
❙ ID: With the soft menu key IDENTIFIER you can set the
triggertoaspecicidentieroraspecicidentierrange.
ThesoftmenukeyCOMPAREdenesthecomparison
function. If the pattern includes at least one X (don’t care),
it is possible to trigger on a value equal or not equal to the
speciedvalue.Ifthepatternincludesonly0or1,itis
possible to trigger on an area greater than or less than the
speciedvalue.ThePATTERNINPUTmaybebinaryor
hexadecimal. If you choose the binary input, the soft
menu key BIT and the universal knob allow you to select
which individual bits within the data are to be edited.
Select the option STATE to assign a logic state to each bit
(High = H = 1, Low = L = 0 or X = don’t care). The state X
denesanystate.Ifyouchoosethehexadecimalinput,
the soft menu key VALUE and the universal knob allow
you to set the value for the respective byte. If the input is
hexadecimal, only the entire byte can be set to X. Use the
soft menu key BYTE to toggle between bytes.
❙ ID AND DATA: The soft menu IDENTIFIER AND DATA
and the soft menu key IDENTIFIER SETUP include the
same settings as the soft menu IDENTIFIER. The soft
menu DATA SETUP allows you to specify the data bit
pattern or HEX values for up to 8 bytes. Available
comparisons for address and data values are EQUAL and
NOT EQUAL.
Press the MENU OFF button several times to close all me-
nus, and the oscilloscope will trigger on the set data. For
measurements without measuring object please refer to
chapter 12.2.2.
Fig. 12.23: LIN data trigger menu