Non-Contact Rotary Position Sensor With J1939 Output For Vehicle Applications

Curtiss-Wright’s Industrial division has launched the NRH27C, a non-contact rotary position sensor which is suitable for on- and off-highway vehicles utilizing CAN Bus communications.

The full range of the digital output span corresponds to a rotation of 360°, and the positional information is determined by the angle of the supplied magnet relative to the sensor body.

The maximum air gap between magnet and sensor is 7mm, while concentric offsets of up to 2mm can be tolerated with minimal impact on output linearity.

The magnet can be supplied in a convenient carrier, housed in a bolt, as a plug or loose.

• Contained in a 9.5 mm low-profile housing
• Small footprint
• CAN Bus J1939 communications
• Fully encapsulated, IP69K-rated design
• Cost-effective solution for medium volume applications where a degree of customization may be required
• Two independent Hall-effect sensing signals allow for error checking of the positional data, which addresses the needs of safety-critical applications
• On-board diagnostic function means predefined error messages can be sent to define the present state of the sensor
• Factory-programmable electronics can be easily set to different Baud rate, Node ID and Frame rates according to system requirements
• Wear-free with no mechanical degradation
• Concentric magnet assembly offsets up to 2 mm
• Multiple magnet options
• Available with industry-standard AMP Superseal, Deutsch DT04 Series connectors, or simple 18AWG flying-leads for customer termination
• Can be powered from a 5V DC regulated or 9-30V DC unregulated supply
• Provides a full 360-degree output range

More Information:

• CW-IG-Overview Brochure (PDF)...
• NRH27C Brochure (PDF)...
• NRH27C Technical Information (PDF)...
• NRH27C-CAN-J1939-Protocol (PDF)...

A Comprehensible Guide to J1939
by Wilfried Voss

SAE J1939 has become the accepted industry standard and the vehicle network technology of choice for off-highway machines in applications such as construction, material handling, and forestry machines. J1939 is a higher-layer protocol based on Controller Area Network (CAN).

It provides serial data communications between microprocessor systems (also called Electronic Control Units - ECU) in any kind of heavy duty vehicles. The messages exchanged between these units can be data such as vehicle road speed, torque control message from the transmission to the engine, oil temperature, and many more.

The information in this book is based on two documents of the SAE J1939 Standards Collection: J1939/21 - Data Link Layer J1939/81 - Network Management A Comprehensible Guide to J1939 is the first work on J1939 besides the SAE J1939 standards collection. It provides profound information on the J1939 message format and network management combined with a high level of readability. Read more...