High-performance SAE J software based protocol stack. Complete J source code is provided. Get on the Bus: J and J Vehicle Bus Standards on established protocols that vary based on vehicle manufacturer, vehicle model. J defines the physical layer, which are the hardware (wiring) and basic protocol that is needed for J and J to transmit messages.

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SAE J is a standard used for serial communications between ECUs on a heavy duty vehicle and also between a computer and the vehicle. It is just strange that not one of the microchip application Engineers get involved in this topic.

J / J Network Operation and Testing – BusTekHub

J also has its own special connector. Characters are transmitted in the common 8N1 format. It defines the physical layer and data link layer. J is mainly used on heavy-duty and commercial vehicles. J Inter-character Bit Time For bytes to be considered as part of a message, the time between bytes is not allowed to exceed 2 bit times.

J uses a twisted pair of wires, with a minimum wire size of gauge. This technology-related article is a stub. Want more from Omnitracs?

The maximum length, from the MID to the checksum, is 21 bytes. Common application and transport layers used on J are J and J For more info, please refer to our forum links: Adding these quickly mandated features prohocol even more hardware and software to be added as standard features on every vehicle.

J Checksum The last byte of every message is the two’s complement of the MID and data contained in the message. This includes bit stuffing at pre-defined intervals the transmitter adding bits that are not part of the message at all. It uses 8, N, 1 byte framing and has a network speed of bits per second bps.


Hallo Thank you for the report back.

J and J Vehicle Bus Standards | Omnitracs

When the voltage difference is less than 0. Hi The Can controller area network on this forum is not a very successful topic I have also questions on this forum about Can It protocoo just strange that not one of the microchip application Engineers get involved in this topic.

The first byte of every message is the MID, which stands for message identifier.

SAE J and J are different on software and hardware. Its my major product, so I rely would like more people to look at this forum.

Get on the Bus: J1708 and J1939 Vehicle Bus Standards

Every message ends with a twos complement checksum. I think that not many eng. If so, if the j protocol is on the rs physical layer, can the CAN be interface to the rs so it can interpret the j protocol???

Part of engineering is learning how to do research and testing your own ideas. Each subsequent priority adds an additional 0.

This standard was put into production vehicles as a standard. For bytes to be considered as part of a message, the time between bytes is not allowed to exceed 2 bit times.

In all other treads i constanly see MC moderator input only at the Can nothing. Essentials Only Full Version. I would have to question the “all the other threads” comment. J is outdated and is currently being phased out of production. However, there are still something similiar: In CAN, the message length is defined as part of the identifier, and is a maximum of 8 bytes.


Debug breakpoints automatically disabled 16F88 cannot set internal oscillator frequency beyond It still has power, ground and J connections in addition j108 the new J wires. And you can not build a large canbus without repeaters. J is a multi-master network tooand it implemented the bus arbitration too, but different than the CAN hardware arbitration, J using softrware. Also, the message length of J is variable up to 21 bytes for standard messages. J Idle Time The bus is considered idle if there is no activity i.

Maybe that there prrotocol not that much interest in this topic??? Since this post were made in January we also advaced great steps in CAN development and I must admit that Microchip Switzerland got on Board with us and supported us with Technical know how and advice.

J Priority In J, each message is defined a priority. J J Vehicle Bus Standards. The only indication of when the message is over is when the transmission stops.

Languages Deutsch Polski Edit links. This means that all the transmitting onto the J bus requires a logic inverter. The priority defines how much additional time must transpire after the bus has become idle before a node may transmit.

Collisions are avoided by monitoring the bus while transmitting the MID to ensure that another node has not simultaneously transmitted a MID with a higher priority. A priority 1, which is the most critical, waits an additional 0.