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Protocol Analysis
R&S
®
RTM20xx
148
User Manual 1317.4726.02 ─ 01
11 Protocol Analysis
With the R&S
RTM and some additional options, you can analyze the following parallel
and serial protocols:
●
SPI (Serial Peripheral Interface with 3 lines) and SSPI (Serial Peripheral Interface
with 2 lines) - requires option R&S RTM-K1
●
I²C (Inter-Integrated circuit bus) - requires option R&S RTM-K1
●
UART/RS232 (EIA-232 serial interface) - requires option R&S RTM-K2
●
CAN (Controller Area Network) - requires option R&S RTM-K3
●
LIN (Local Interconnect Network) - requires option R&S RTM-K3
●
Audio (I2S, LJ, RJ,TDM) - requires option R&S
RTM-K5
11.1 Basics of Protocol Analysis
The analysis of serial data consists of three main steps:
●
Protocol configuration: Select the protocol type, and configure the input line as well
as the protocol-specific settings
●
Decoding: Configure the display of the decoded data and enable decoding. As a
result, the digitized signal data is displayed on the screen together with the decoded
content of the messages.
You can scale the signal display and zoom into it to see it in more detail.
You can create and apply label lists for easier identification of the bus nodes on the
display.
●
Triggering: You can trigger on various events that are typical for the configured bus
type, for example, on start and stop of messages, on specific addresses, or on serial
patterns.
Analysis can be performed on analog input channels, and - if MSO option R&S
RTM-K1
is installed - on digital channels.
11.1.1 Configuring Common Protocol Settings
Common settings for all bus types are the logic threshold and the decoding and display
settings.
If the MSO option R&S
RTM-B1 is installed, and the digital channels are used for protocol
analysis, the thresholds are set in the "Logic" menu.
To set the logic threshold for analog channels
Before you start configuration and analysis, check and set the logic thresholds for all used
channels - the voltage values for digitization of analog signals. If the signal value is higher
than the threshold, the signal state is 1. Otherwise, the signal state is considered 0 if the
signal value is below the threshold.
Basics of Protocol Analysis