imc CANSAS-SENT

Providing a gateway from SENT to CAN

From the start, the automotive industry has always employed up to date measurement technology, thus, forcing the substitution from traditional analog sensors to more cost-effective digital data transmission in vehicles. With the introduction of the SENT protocol, safety is also increased when transmitting data from the sensor to the ECU.

imc CANSAS-SENT at a glance:

Gateway from SENT to CAN
Supports all sensors with SENT output
8 isolated SENT inputs; channel to channel and channel to GND isolation
Supports fast and slow channels
Each imc CANSAS-SENT input channel can handle up to four high-speed sensor channels
imc CANSAS is part of a universal measurement-module family with CAN output
imc CANSAS software allows convenient setting options

Overview

Rugged, economical, easy-to-use

imc CANSAS-SENT is a versatile, flexible and cost-effective gateway that offers direct and easy access to SENT sensor data in various applications. Unique in the market, the imc CANSAS-SENT gateway converts data from SENT to CAN, thus, allowing for direct access of recorded CAN data from any data acquisition, testing or automation system. The advantage: SENT sensors are seamlessly integrated into measurement systems using a variety of signals, including analog signals, busses and other vehicles of digital I/O.

Manufacturers of SENT sensors can especially benefit from the new imc CANSAS-SENT module. The module is a simple tool that supports the testing processes of sensors, as well as the development and testing phases of ECUs/control devices. As a member of the imc CANSAS family, the module is optimally designed to work with data acquisition systems such as the imc BUSDAQ, imc CRONOSflex or the imc C-SERIES.

SENT protocol

Information on the SENT protocol

SENT stands for Single Edge Nibble Transmission. SENT is a relatively new digital interface for intelligent, active sensors with internal digitization and allows for a cost-effective and flexible replacement of conventional analog sensors. The aim of the SENT protocol was to increase durability/quality and to reduce the complexity when transferring data from the sensor to the control unit (ECU). Currently, SENT protocol is mainly used in the automotive industry, however, other applications are quite conceivable.

The SENT protocol (J 2716) is an open standard, released in 2008 by the Society of Automotive Engineers (SAE).
Compact, inexpensive and a simple protocol with three wires - supply voltage = 5V, signal voltage L <0.5 V, H> 4.1 V and ground. The wires are unshielded and untwisted.
Directional, one-way connection between sensor and receiver
A data volume of 4 bits per pulse (a "nibble") is transmitted via transport protocol. The pulses are evaluated only on the basis of the falling edges, hence the name "Single Edge". The information content (data value of nibbles) is encoded on the pulse length.
The data rate via SENT protocol depends on two factors:
1. "Tick length": this can vary from 3μs-90μs. The tick length represents a previously valued baseline of time.
2. "Pause pulse frame": this defines the distance between the frames.
A data packet is comprised of 24 bits (6 nibbles) for measurement data, and 8-bits (2 nibbles) for error detection, status and communication. The primary measurement data are transmitted via FAST channels. Information such as sensor manufacturer, type of sensor, calibration and configuration is transmitted via SLOW channels.
SLOW channels are transmitted less frequently than FAST channels.

Passive monitoring

One particularly special feature of the imc CANSAS-SENT is “passive monitoring”. Wired parallel to the existing setup between a SENT sensor and a control device (e.g., ECU), the imc CANSAS-SENT module not only provides the gateway (conversion) to a CAN signal output, but it also won’t interfere with the existing communications of the test object. That is, it allows a reactionless (passive) monitoring of the signal. The transmission can quietly be listened to without disturbing or interfering with it.