Au SAE J1708 to J1939 gateway (part # GW2-1708-1939) is able to convert 24 signals from SAE J1708/1587 network to J1939 network. It is designed for trucks with SAE J1708/J1587 network only. It will add a J1939 network to those trucks.

Supported Parameters

Features

• Power Supply: Operating range: 10V ~ 32V DC ; nominal voltage: +12V DC or +24V DC
• Operating Electric Current: 65mA typical, 250mA max
• Operating Temperature: -40°F to 185°F (-40°C to 85°C)
• Size: 3-1/8 inch L X 1-11/16 inch W X 13/16 inch H (78mm X 42mm X 21mm)
• TVS (Transient Voltage Suppressor) protection on J1939 and J1708/J1587 bus
• Enclosure Color: Black and translucent red
• 1 LED (Communication)
• 1 RS232 interface (DB9 female connector): can be connected to PC or any device with RS232 serial port for device running status monitoring and in-field programming ( default RS232 baud rate: 115.2K)
• 1 BUS interface (DB9 male connector): can be connected to J1939/CAN, J1708/J1587 network, and a power supply (+14.2V DC nominal). The pin-out of the DB9 male "BUS" interface is illustrated in following pin-out diagram:

Pin out Definition

Hardware Connection

Following is an example of how GW2 (Au J1708 to J1939 gateway) was used in the lab environment, Au J1939 Data center was used to capture PGN 65265, 65248, 65253 on J1939 / CAN network, the result is displayed on Au J1939 Data Center PC GUI. Optional PC was used for data displaying purpose. Two 120-ohm terminal resistors must present on each end of the J1939 network backbone.

In the above demonstration, J1708 ECU broadcasts "road speed" and "total vehicle distance" signals on J1708 network. Au GW2 receive these two parameters (road speed, odometer signals) on J1708 network . Then it will perform the following:

• Convert J1587 "Road Speed" to J1939 "wheel based road speed" and transmit PGN 65265 on J1939 / CAN network.
• Convert J1587 "Total Vehicle Distance" to J1939 "Total Vehicle Distance" and transmit PGN 65248 on J1939 / CAN network.
• In the mean time, it also output ASCII string on RS232, which can be displayed on PC screen using Tera Term (open source serial communication software) for monitoring purpose, please see details at the next paragraph for AT command.

In the above demonstration, a J1939 device (Au J1939 Interpreter) was used to send out Engine Hour request command to J1939 network (using PGN 59904), once GW2 receive the request, it will send the request to J1708 ECU, then J1708 ECU will reply with the current Total Engine Hours and send it over to J1708 network (PID 247). GW2 then convert Total Engine Hour to SAE J1939 Engine Hour and transmit SPN 247 (PGN 65243) on J1939 / CAN network.

Engine Hour data flow is illustrated here:

Water proof version of GW2 hardware is also available