Protocol analysis
R&S
®
RTO6
635
User Manual 1801.6687.02 ─ 05
SENT is a protocol standard governed by Society of Automotive Engineers (SAE
J2716). For detailed information, refer to the SENT standard specification on
The SENT protocol is used exclusively in automotive applications, as for example elec-
trical power steering, advanced driver assistance like parking assist or sensing of pres-
sure, throttle position, pedal position, airflow mass, liquid level, etc.
The R&S
RTO6 option R&S
RTO6-K520 provides serial triggering, decoding and a
highly customizable search on decoded SENT signals.
13.10.1
The SENT protocol
This chapter provides an overview of the protocol characteristics, encoding scheme,
identifiers and trigger possibilities.
The SENT protocol transmits signal values point-to-point from a sensor to a controller
(electronic control unit ECU), unidirectional. In contrast to conventional measurements,
you can receive multiple data parameters via the SENT interface in a single transmis-
sion. Nevertheless, SENT is characterized by its simplicity and yet very high customiz-
ability to meet the individual requirements of the applications.
SENT operates via a three wire connection, a signal line, a supply voltage line for the
sensor and a ground line. It transmits data digitally in variable timing units and evalu-
ates the time between two falling edges (single edges). The signal is amplitude modu-
lated with a constant amplitude voltage. Thus influences of interfering signals are not
critical.
SENT key features
Main characteristics of SENT are:
●
serial communication protocol
●
3 wires: SENT (signal line), 5V (voltage line), GND (ground line)
●
output only, from sensor to receiver
●
point-to-point transmission, no bus
●
digital transmission
●
high baud rate
●
data transmission in variable timing units of 4 bits (1 nibble) between two falling
edges
●
transmitter-specific clock period (tick)
●
time measured between single falling edges
13.10.1.1
SENT transmission concept
A sensor converts the analog measured data to a digital signal, and thus transmits a
series of pulses to the receiver. The receiver, e.g. an ECU processes the received sig-
nal also digitally.
SENT (option R&S
RTO6-K520)
