SAE J1939 and J1708 is the vehicle bus standard used for communication and diagnostics among vehicle components. Based on the same architecture FMS protocol dedicated to telematics systems is available.
- SAE J1708 is a standard used for serial communications between ECUs on heavy duty.
The hardware utilized is RS-485 transceivers wired for open collector operation through the use of a pullup and pulldown of the separate data lines.
J1708 functionality is used to read vehicle's Fuel Level and Fuel consumption.
Because fuel CAN data J1708 is not a CAN-BUS protocol, FMB640 CAN1 and CAN2 lines cannot be used to read J1708 information. FMB640 has a special J1708 Port, which utilizes an RJ9 4P4C connector.
- FMS CAN data(J1939), or Fleet Management Systems Interface, is a sector to configure and manage events based on vehicle data of commercial vehicles. Vehicle data comes through CAN line.
The FMS standard defines a gateway between the J1939 vehicle network and a fleet management system.
FMS Standard lower layer protocols:
- Application layer – SAE J1939/71
- Data link layer – SAE J1939/21 (FMS data are coded according to SAE J1939)
- Physical layer – ISO 11898-2 High-speed CAN, 250 kbit/s bus speed
- Physical connectors – Not standardized
| time | version | common name | notes |
|---|---|---|---|
| 2002 | 1.0 | Truck FMS Standard | Initial release |
| 2007 | 00.01 | Bus FMS Standard | Specialized for buses and coaches including specific signals like door openings, etc. |
| 2010 | 02.00 | Truck FMS Standard | It took over some signals from the Bus FMS Standard, but still handled separately for Trucks. |
| 2012 | 03 | FMS Standard | Harmonized Bus and Truck standard (with separated sections inside for buses and trucks). |
| 2017 | 04 | FMS Standard | Harmonized Bus and Truck standard (with adding Cruise control states) |
direct J1708/J1939 connection
Teltonika FMB640 FMX640 offers the following options for direct J1708/J1939 connection:
- through the 2x10 socket (front side)
- SAE J1939, CAN 1, FMS
- SAE J1939, CAN 1, raw/manual (i.e. without FMS)
You get raw CAN data from the vehicle CAN lines. Please- configure required data filters on FMB640 and
- setup your server to correctly interpret the raw data received from FMB640.
- SAE J1939, CAN 2, FMS
- SAE J1939, CAN 2, raw/manual (i.e. without FMS)
You get raw CAN data from the vehicle CAN lines. Please- configure required data filters on FMB640 and
- setup your server to correctly interpret the raw data received from FMB640.
- through the J1708 socket (back side, RJ11 port)
- SAE J1708 (actually RS-485 at physical layer)
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references
- FMB640 SMS/GPRS command list
- https://wiki.teltonika-gps.com/view/FMB640_LVCAN_I/O,FMS_IO_and_Tachograph_data_elements
- https://wiki.teltonika-gps.com/view/FMB640_Teltonika_Data_Sending_Parameters_ID#FMS_elements
- https://wiki.teltonika-gps.com/view/FMB640_J1708
- https://wiki.teltonika-gps.com/view/FMB641_CAN_%5C_Tachograph
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FAQ
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Q: Are SAE J1939 ports read only?
A: Yes, they are.
Q: Where do I get the SAE J1939 wiring diagram for a vehicle?
A: Please contact
support@mirifica EU us,
maybe we have the right SAE J1939 wiring diagram for the vehicle.
If not, you shall contact the vehicle manufacturer or one of its authorized service centers.
Q: What is the difference between CAN1 and CAN2?
A: It depends on specific vehicle manufacturer and model. Sometimes data are transmitted on CAN1, sometimes on CAN2. The best practice to find the correct CAN line is by trial: connect and check on PC if data is coming.
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Q: Where I can find the SAE J1708 connector on a vehicle?
A: It is the vehicle's diagnostic port. The exact location:
- should be provided by vehicle manufacturer or
- could be found in vehicle documentation.
Q: Where can I find the SAE J1708 wiring diagram for a vehicle?
A: SAE J1708 connection (pin-out) diagram can be found in FMB640 documentation, in "J1708 Connection" section.
Q: Is SAE J1708 port read only?
A: Yes, it is.
Q: What SAE J1708 data can I read from a vehicle?
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- Fuel Level
- Engine Total Fuel Used
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Q: What FMS data can read out of my vehicle?
A: Please contact the manufacturer of your vehicle or an authorized service center.
What FMS parameters are issued depends on vehicle manufacturer, model and year of production. The vehicle manufacturer decides what FMS data are issued by and FMS gateway.
Q: What FMS data can FMB640 read out?
A: FMB640 can read out the following FMS data:
- Accelerator pedal position (0–100%)
- Brake switch (on/off)
- Clutch switch (on/off)
Cruise control (on/off)
Distance
- High-resolution vehicle distance
- Service distance
- Fuel
- Fuel level (0–100%)
Total fuel used (litres since lifetime)
- Gross axle weight rating (kg)
- Engine:
Engine coolant temperature
Engine speed
- Total engine hours (h)
FMS-Standard software version (supported modes)
- PTO (Status/Mode)
Tachograph information
Vehicle
- VIN = vehicle identification number (ASCII)
Vehicle improvement (all round)
Vehicle speed (wheel based)
- Vehicle speed (from tachograph)
Q: What FMS data can FMB640 read out of my vehicle?
A:
A.1: connect FMB640 to FMS interface (vehicle CAN lines without any adapter or converter) [image];
A.2: turn vehicle ignition on;
A.3: send SMS command " scanfms" or "[user] [pass] scanfms";
A.4: you will receive an SMS reply with the list of parameters that are read out by FMB640 through FMS.
Q: Can FMB640 read FMS Fault Codes?
A: As of 2019-03, FMB640 cannot read FMS Fault Codes, but its implementation is under development.
Q: Where do I get the FMS connection in my vehicle?
A: Please contact the manufacturer of your vehicle or an authorized service center.
The FMS connector has not been standardized. It is typically a green rectangular receptacle connector.
Q: Where do I find the FMS wiring diagram for my vehicle?
A: Please contact the manufacturer of your vehicle or an authorized service center.
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Q: Which protocols are supported by my vehicle?
A: Please contact the manufacturer of your vehicle or an authorized service center.
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Q: What I/O elements can FMB640 directly read?
A: FMB640 can read those I/O elements through a direct wired connection listed in Teltonika Configurator, under FMS I/O settings
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Please note that your vehicle may not support all parameters.
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Q: Can FMB640 read OBD-II data through a direct wired connection?
A: No, FMB640 cannot read OBD-II through a direct wired connection.
You may use a third-party ODB-II/serial adapter cable and
connect it to the COM1 port;
receive OBD-II data;
send OBD-II data to the server using TCP Binary Mode (Codec12) protocol.
Q: Can FMB640 read OBD-II data through a direct wireless connection?
A: No, as of 2019-04, FMB640 cannot read OBD-II data through a direct wireless connection (e.g. ODB-II/Bluetooth adapter).
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Q: Can FMB640 read serial data remotely?
A: Yes [link]:
A.1: read raw data from serial port;
A.2: send raw data to server through TCP Binary/ASCII mode;
A.3: read raw data from server;
A.4: parse raw data.
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Q: Is it possible to connect fms to FMB640 directly?
A A: If you would like to connect FMS to FMB640, you can connect it directly to FMB640 CAN lines without any adpaters or Converters, please see this link:
https://teltonika-gps.ltcom/downloads/en/fmb640/FMB640-wiring-full.png
CAN1L and CAN1H can be connected to the FMS lines directly to read FMS data.
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Q: How to get the parameters received by the fms by sms?
A: After connecting FMB640 to FMS and by sending SMS command "scanfms", you will receive a response with parameters that are received from FMS. (Igniton of Truck has to be On)
https://wiki.teltonika.lt/view/FMB_scanfms
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Q: Can we use the RS232 port for FMS data?
A: By using a RS232 converter to connect to FMB640, you would have to use TCP Binary/ASCII mode. But you will receive all data from FMS unparsed (you would have to parse data from the server side).
https://wiki.teltonika.lt/view/FMB640_RS-232_and_RS-485
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Q: How can we do if the GPS module reports that it is ON, but there is no GPS signal ?
A: Check if the power source does provide enough power for device to start, which is between (10-30) V DC. Then, the device will leave the hibernation state.
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Q: How does the tcp link work in FMB640?
A: TCP link mode works like a "tunnel" connecting RS232 device with the server. FMB640 simply acts like a "data tunnel".
Using TCP link mode, each time RS232 message is received, FMB640 would re-sent RS232 data to the server. This requires that FMB640 is connected to the server 24/7 and always has open data link with the server, because TCP link mode only works when device has open data link with the server.
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Q: Does FMB640 support modbus ?
A: FMB640, FM63 and FMB125 support RS485, can support MODBUS. But functionality is not available, thus special development is required.
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