User manual

45
Mixed-Signal Operation
11 Mixed-Signal
Operation
As a standard, the R&S®HMO Compact series is equip-
ped with the connectors for the R&S®HO3508 logic probe
to add 8 digital logic inputs. All software required for the
mixedsignaloperationisalreadyincludedinthermware
of each instrument. It is only necessary to purchase and
connect the active R&S®HO3508 logic probe (8 channels).
With 4-channel instrument types the activation of the POD
will deactivate the analogchannel3.Thecongurationof3
analog channels plus 8 digital logic channels are possible.
11.1 Logic Trigger for Digital Input
11.2 Display Functions for the Logic Channels
With the 4-channel instrument types the short menu is
used to switch an analog channel to a digital channel. If
channel CH3 is activated and the short menu is displayed,
the digital channels 0 to 7 can be switched on via PO soft
menu key. To switch on the digital channels with 2-chan-
nel instrument types, press the POD key in the VERTICAL
section. The digital channels 0 to 7 will now display on the
screen.
For the logic channels, a logic „1“ will be indicated by a bar
that is two pixels wide, and a logic „0“ will be indicated by
abarthatisonepixelwide.Thesetlogiclevelandagure
which shows the logical states will be shown next to the
namePODintheinformationeldinthebottomleftofthe
display.
Fig. 11.1: Optional logic probe R&S®HO3508
Please nd an additional description of the logic trigger for the
inputs of the logic probe in chapter 6.5.
You must always set the level to distinguish between the logic
states (High/Low) in the VERTICAL MENU..
You may now choose the Y position and the size of the lo-
gic channel display just as you would for the analog chan-
nels. Use the knobs Y-POSITION
18
and VOLTS/DIV
20
to
select the settings (if the soft menu key “0/7“ is selected,
indicated by a blue background). If you wish to display fe-
wer than 8 logic channels or change the position and size
of a particular logic channel, you can use the short menu
in combination with the soft menu keys (channel 0 to 7)
and the buttons Y-POSITION
18
and VOLTS/DIV
20
to se-
lect the respective settings. You can choose a channel by
pressing the
and soft menu keys. This allows you to re-
sizeandpositionspecicchannelsindividually.
You can reset the position and size of the individual lo-
gic channels on page 2|2 of the POD menu. You also have
the option to label the individual bits of the logic chan-
nel by using the soft menu NAME. This name will be dis-
played on the gridandtheprintout.Yourrstoptionisto
switch the display on (ON) or off (OFF). The next option in-
cludes the menu item LIBRARY. After selecting this option,
you can use the universal knob to choose a name from se-
veral suggestions. The EDIT LABEL key allows you to en-
ter a completely new name or to customize the suggested
name. You may enter up to 8 characters. Use the ACCEPT
keytoconrmthenameintheeditor.Itwillthenbeshown
inthedisplay.Thenameisassignedtothatspecicsignal
and will move alongside any set offset value.
11.3 Display of Logic Channels as BUS
You also have the option to combine digital channels to
form buses which will then be displayed on the screen as
a cell in a table. Basically, two independent buses are pos-
sible. For instance, it would be possible to combine an 8
bit address bus and an 8 bit data bus. To select the set-
tings for the buses, press the BUS button in he VERTI-
CAL section. Then press the MENU button in the VERTI-
CAL section. In the menu that opens you can press the top
soft menu key BUS to select which BUS you want to de-
ne,B1orB2.YoucanusethesoftmenukeyBUSTYPE
to choose the BUS type for the display and the analy-
sis. The BUS type determines the bus structure and is or-
ganized differently depending on serial vs. parallel or the
Fig. 11.2: Logic channels’ settings display