SAE J1939 datalink is a high-speed network for machines that operate at a 250K baud rate. J1939 is capable of supporting control, information sharing, diagnostics, multiplexing and proprietary communications. The J1939 (physical layer) datalink uses a differential line driver circuit and allows a maximum bus length of 40 meters. The network can have a maximum of 30 node connections at any given time.

We design and build the following J1939 bus interfaces:

J1939 Shifters - We design and build the J1939 shifters for Allison, Twin Disc and Cater Pillar transmissions with the speed range from 6sp to 8sp.

J1939 FRAC controllers - We design and build the remote and local controls with J1939 Bus for FRAC engines. These controllers are equipped with beautiful color monitor displaying engine and transmission parameters.

J1939 Speedometers - We design and build the speedometer interface using J1939. This interface converts transmission output speed to J1939 vehicle speed and distance. Basically it converts the revolutions of the output shaft of the transmission to a J1939 compatible signal to determine speed and distance. Speed and distance can be displayed using an optional readout like PV100 Murphy Power View. Revolutions/mile, gear ratio and teeth are programmable via an RS-232 connection.
J1939 speedometer specification