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 Throttles - are microprocessor based products that generate corresponding J1939
command based on the input, which is the required signal to throttle the ECM from
0-100%. Air pressure, switch, 4-20mA, 0-9V/1-9V and RS-232 can be used as inputs to
generate the J1939 commands.
Download J1939 throttle specification
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.
Download J1939 speedometer specification