Specifications

34
Subject to change without notice
BIT and NEXT BIT, then use the universal knob for the linking
to the logic channel.
If you chose the bus type PARALLEL + CLOCK, the lower two
soft menu keys are reserved for the source and the slope of the
clock. For selecting the source of the clock, press the key CLOCK
and use the universal knob for selecting the logic channel which
carries the clock. The key SLOPE will offer RISING, FALLING and
BOTH in that order and start all over. The activated selection
will be shown with a blue background. Pressing the MENU OFF
key will return you to the BUS menu. There is another menu
item DISPLAY SETTINGS. In this submenu selecting DISPLAY
will allow to select the following decoding formats with the
universal knob:
– Binary
– Hexadecimal
– Decimal
– ASCII
The decoded values will be shown in the tables of the buses in
the format selected.
The next lower soft menu key may be used to switch the in-
dividual bits of the bus on in the table display. The BUS short
menu will be displayed upon pressing the MENU OFF key twice.
The two upper soft menu keys can be used to switch the bus
display on or off. If a bus is switched on, this will be indicated
by a white dot in the short menu. In order to vary the position or
the size of a bus, it is rst selected in the menu which is shown
by a blue background of the key. The position control knob is
used to position the bus display on the screen. The size of the
table display can be varied with the VOLTS/DIV knob. This may
be especially helpful in case of the binary format, because it
allows to display the complete value in up to 4 lines even with
short tables.
11.3 Cursormeasurementsforthelogicchannels
If the logic channels were activated, some parameters may be
measured with the cursors. For all activated logic channels
of a POD these measurements are available: TIME, RATIO X,
V–MARKER. The results will be as follows:
TIME:
The time position of both cursors relative to the trigger time
position will be indicated; also the time difference between the
two cursor positions from which the frequency is calculated.
RATIO X:
In this mode 3 cursors are used. The time ratios between the
rst and the second and between the rst and the third will
be shown. The presentation will be in oating point format, in
percent, in degrees, and in radians.
V–MARKER:
With the logic channels the logic value of the selected POD will
be measured at the position of the respective cursor and shown
in hexadecimal and decimal formats.
12 Serial bus analysis (optional)
The HMO2524 with option HOO10 can be used for triggering
and decoding of I 2 C, SPI and UART/RS-232 buses on the di-
gital inputs (Option HO3508/16). The option HOO10 requires at
least the rmware 2.0 in the HMO, it will become usable with
a software licence key. This key will either be installed during
manufacturing or by the user when he installs an update as
described in chapter 2.10.
In order to establish the settings of the trigger and decoder func-
tions, it is necessary to rst dene a bus. A maximum of 2 buses
B1 and B2 can be dened. First press the key BUS/REF in the
VERTICAL area of the front panel, a short menu will open. Use
the lowest soft menu key to either select whether references
or buses are to be dened. This is a toggle key which alternates
between those two possibilities RE (reference) and BU (bus).
The activated function is indicated by a white background. Here
select BU. Then press the MENU key in the VERTICAL area of
the front panel. A menu will open, the top soft menu key allows
to choose either B1 or B2.
Fig. 12.1: Bus denition menu
By pressing the soft menu key BUS TYPE the type of bus can be
selected from the available ones. If the option HOO10 is installed,
there will be these options:
– Parallel
– Parallel clocked
– SPI 2 wire
– SPI 3 wire
– I
2
C
– UART
Mixed Signal Operation
Fig. 12.2: Menu for the selection of the decoding format