Site Information

 Loading... Please wait...

Blog

SAE J1939 Monitor Software - Setting Up PGN Simulation Such As Engine Coolant Temperature

Posted by Wilfried Voss on

In this post, I will explain the setup of SAE J1939 PGN simulation with our JCOM1939 Monitor software, and I will use the Engine Coolant Temperature as a randomly chosen example. Let me emphasize the point that you can set up any PGN with our software. However, please be also aware that you will need the SAE J1939-71 Standard (available as a download, currently priced at US$81) as a reference, as it documents all standardized PGNs, their data format, and transmission frequency.

A few notes before we look into the details:

PGN 65262 Engine Temperature 1

According to the SAE J1939-71 Standard, the Engine Coolant Temperature is part of PGN 65262; it is the first byte in the 8-Byte data field as defined by SPN 110. SAE J1939-71 also states that the data is transmitted using a one-second interval.

SPN 110 explains the coolant temperature format:

  • Length = 1 Byte
  • The format is one degree Celsius per bit, with a -40 degree C offset.
  • The temperature range is from -40C (-40F - 0x00) to +215C (419F - 0xFF).

SPN 110 - Engine Coolant Temperature Setup

In the following, we are using our SAE J1939 ECU Simulator Board with USB Port, however, the choice of hardware has no impact on the setup process.

As shown in the following image, the device connects per the COM3 port to the software (this is the default but may be different on your computer). 

In order to set up and transmit any PGN, we need to assign a node address to the simulator. In all consequence, you should also set up the NAME of the device, but in our example, we go with the default settings. In regard toi the node address, we'll go with the default address, too, which is 128.

Note: The node address range range allows the simulator to find an address other than 128, in case that 128 is already taken in the network. If a new address was determined, it will be reported back to the JCOM1939 software.

Now, in order to start the address negotiating process, you need to engage the ECU Simulation Mode as shown in the image and click on the Claim Address command button. The JCOM1939 Monitor program will display the valid node address.

SAE J1939 Simulator Setup - Node Address

In reference, see the raw CAN Bus data frame for claiming node address 128:

SAE J1939 Simulator Setup - Node Address Hex Code

In the Transmit section of the JCOM1939 software, set up PGN 65262 as shown in below image. In our example, I have set up byte #1 as 0xFF, representing the coolant temperature; the remaining data are set to 0x00 just to separate them visibly.

SAE J1939 Simulator Setup - PGN Design

When you click the Save command button, the device will start the data transmission. For a reference, see also the raw CAN Bus data:

SAE J1939 Simulator Setup - PGN Design Hex Code

Engine Coolant Temperature - Simulation

There are two ways of simulating the engine coolant temperature: 1. Through editing the data string or 2. Using a slider as provided by the JCOM1939 software. I chose the slider, because it is by far more exciting to use.

In the JCOM1939 software, switch over to the Byte Data section, select PGN 65262, set Start Position to 1 and Length to 1 as shown in the image below. Now move the corresponding slider and watch the data change:

SAE J1939 Simulator Setup - Simulating Coolant Temperature

Last, but not least, here is the raw CAN Bus data:

SAE J1939 Simulator Setup - Simulating Coolant Temperature Hex Code

And yet again, you can set up any PGN and simulate any data associated with that PGN by using the slider (analog data) or switch to the Bit Data section to simulate digital I/O signals.


A Comprehensible Guide to J1939

a-comprehensible-guide-to-j1939-by-wilfried-voss.jpg

SAE J1939 has become the accepted industry standard and the vehicle network technology of choice for off-highway machines in applications such as construction, material handling, and forestry machines. J1939 is a higher-layer protocol based on Controller Area Network (CAN Bus).

It provides serial data communications between microprocessor systems (also called Electronic Control Units - ECU) in any kind of heavy duty vehicles. The messages exchanged between these units can be data such as vehicle road speed, torque control message from the transmission to the engine, oil temperature, and many more.

The information in this book is based on two documents of the SAE J1939 Standards Collection: J1939/21 - Data Link Layer J1939/81 - Network Management A Comprehensible Guide to J1939 is the first work on J1939 besides the SAE J1939 standards collection.

It provides profound information on the J1939 message format and network management combined with a high level of readability.

Read More...

Dual Isolated CAN FD Interface Board For Raspberry Pi, Arduino, And Other Embedded Systems

The 2-Channel CAN Bus interface board by Copperhill Technologies was primarily designed with the Raspberry Pi in mind but is, nevertheless, also suitable for other embedded systems such as the Arduino family of CPU boards. The board supports two CAN FD (CAN with Flexible Data-Rate) ports with a data rate of up to 8Mbps. It features [...]

Read More »


Industrial IoT 4G LTE Router & Gateway With Ethernet, RS232, RS485 Serial Ports Plus Digital I/O

The ICR-3200 LTE gateway by Advantech represents an excellent solution to connect IP or serial devices to a cellular network, allowing industrial M2M and IoT applications that comprise of kiosks, industrial PCs, HMIs, traffic controllers, meters, UPS systems, and more.Supporting LTE Cat.4 upload speeds of up to 50 Mbps and download speeds of up to 150 Mbps, the [...]

Read More »


CAN Bus And SAE J1939 Prototyping With The Arduino Due ARM Cortex M3 Processor

Whenever it comes to building rapid prototypes for new CAN Bus or SAE J1939 applications, my first choice is regularly the Arduino Due, a microcontroller board based on the Atmel SAM3X8E ARM Cortex-M3 CPU.In general, the Arduino platform couples an easy-to-use programming environment (IDE) with a vast number of hardware extensions (shields). While I do appreciate programming [...]

Read More »


Industrial IoT Gateway With CAN Bus Port Compatible With Windows 10 IoT And Linux Operating Systems

Axiomtek, a design and manufacturing company in the industrial computer and embedded field, announced its ICO320-83C, a fanless DIN-rail embedded system with four RJ-45 Gigabit PoE ports for facility monitoring systems, IP video surveillance, Access Point, and intercoms.It represents an industrial IoT gateway that comes with IP40-rated heavy-duty aluminum extrusion and steel enclosure for application [...]

Read More »


Raspberry Pi PICAN2 Functionality Test With Two PICAN2 HATs

The following is yet another post on testing the PICAN2 - CAN Bus Interface for the Raspberry Pi, however, with a different approach. In this case, we utilize two identical PICAN2 boards and connect them per the CAN Bus (CAN_H to CAN_H, CAN_L to CAN_L) as shown in the image above.In the past, we have [...]

Read More »


SAE J1939 to Bluetooth Gateway - Android Code (Java) Sample Code

Just as a fair warning upfront, the code that I am referring to in this post is not a finished sample code, but it demonstrates how to receive and decode SAE J1939 message frames (PGNs) from our JCOM Bluetooth device.  To explain the situation: Some time ago, we had started a customer project with the intention [...]

Read More »


SAE J1939 Data Logger Produces Excel-Compatible Files For Further Processing

Our free-of-charge JCOM1939 Monitor Software for Windows is a complete tool to monitor, analyze, record, and simulate SAE J1939 data traffic. It works in combination with our SAE J1939-USB gateways.  The monitor software represents a comprehensive and easy-to-use, easy-to-understand tool that displays not only SAE J1939 data traffic; it also allows scanning the network, simulating an [...]

Read More »


Low-Cost Cloud IoT Development Kit Supports Microsoft Visual Studio And Azure

The MXChip AZ3166 IoT Development Kit, as its name implies, is made for building cloud-enabled IoT apps in a productive and entertaining way.The development kit provides a smart hardware solution. It is compatible with the Arduino platform with abundant peripherals and sensors. The AZ3166 can be used for the development of IoT and smart hardware prototypes, [...]

Read More »


SAE J1939 Gateway Module With Updated JCOM1939 Monitor Software

The following is an update on the development (firmware plus supporting Windows monitoring tool) of our newest product, the SAE J1939 Gateway Module With USB Port, RTC, MicroSD Memory Card as shown here to the left.  The JCOM.J939.USB-X SAE J1939 Processor board is an extended version of our popular JCOM.J9139.USB-B SAE J1939 ECU Simulator Board With USB [...]

Read More »