User Manual

Acquire the Sign
al
4. Push Thresholds to configure the high and
low thresholds for the ARINC429 bus being
acquired or se
lect from available presets.
Bus B1
AR-
INC429
Define
Inputs
Thresh-
olds
800mV
0.00 V
Configure
B1 Label
AR-
INC429
Bus
Display
Event
Table
5. Push Configure and select the appropriate
side menu choi
ces.
Bit Rate
100 kbps
6. Push Bit Rate, and turn Multipurpose a to
select from
the list of predefined bit rates.
Alternatively, you can set the bit rate to a
specific value. To do so, select Custom, and
then turn Mu
ltipurpose b to set the bit rate
from 10 kbps to 1 Mbps
DATA
Format
DATA
7. Push DATA f
ormat, and turn Mu ltipurpose a to select from the size of the data field for packets being decoded on
the ARINC429 bus.
I
2
CBus
To acquire data from an I
2
C bus, you need to also set up these items:
1. If you select I2C, push Define Inputs and the
appropriate side menu choices.
Bus B1
I2C
Define
Inputs
Thresholds Include
R/W in
Address
No
B1 Label
I2C
Bus
Display
Event
Table
You can assign the predefined SCLK Input
or SDA Input to the channel connected to
the signal.
2. Push Include R/W in Address and then
push the desired side button.
This control determines how the oscilloscope
shows the I
2
C addresses in bus decode
traces, cursor readouts, Event Table listings,
and trigger settings.
If you select Yes, the oscilloscope displays 7-bit addresses as eight bits, w here the eighth bit (LSB) i s the R/W bit. It
displays 10-bit addresses as 11 bits where the third bit is the R/W bit.
If you select No, the oscilloscope displays 7-bit addresses as seven bits, and 10-bit addresses as ten bits.
In the physical layer of the I
2
C protocol, 10 bit I
2
C addresses are preceded by the five bit code, 11110. The oscilloscope
does not include these five bits in address readouts.
72 MDO3000 Series Oscilloscopes User Manual