J1939 Protocol
A new innovation is added to the automotive sector every day. New regulations are made every day to make automobiles more practical and automotive systems safer.
SAE (The Society of Automotive Engineers), known for regulations in the automotive sector, arranges new protocols. We have previously mentioned the J2534 protocol. In today's article we will discuss the J1939 protocol.
What is the J1939 protocol? Why was it created?
The basic purpose of this J1939 protocol is to provide in-vehicle communication. This J1939 protocol was developed by SAE. It provides users with advantages in communication between ECUs in the vehicle and in fault diagnosis. The J1939 protocol uses the CAN bus line and offers a common language to all users.
This J1939 protocol was first developed for use in trucks and trailers in the USA. This protocol is generally used intensively in heavy-duty vehicles, construction machinery, agricultural vehicles, construction vehicles and vehicles containing industrial diesel engines.
The most important feature that distinguishes this protocol from others is its data broadcasting capability. In other words, the main purpose of this protocol is to broadcast data and it is highly developed in this direction. This protocol provides very fast data transmission between ECUs in heavy-duty vehicles.
Examples of this data include vehicle speed, oil temperature and torque. J1939 data consists of actual data and headers and contains indexes called PGN (Parameter Group Numbers). PGN defines the incoming data. With J1939, a standard has been created for these PGNs.
General features of the J1939 protocol;
To summarize the general features of this J1939 protocol;
-Provides communication between ECUs in heavy-duty vehicles.
-Uses the CAN communication system, therefore it is a high-standard communication protocol.
-Twisted-pair cable is used in this protocol.
-Supports a maximum of 30 nodes in the ECU.
-Contains 253 control applications.
-Provides communication at 250 Kbit/sec speed
-Supports all messages up to 1785 bytes in size.
-Also supports the PGN indexes we mentioned earlier.
In short, this protocol is a protocol created by SAE to provide communication and data flow in all vehicles classified as heavy-duty in a highly fast and effective way.