Small 'farm' factors power machinery

Fire engines, agricultural equipment, and similar machines often involve mobile automation. ISO 11783, also referred to as ISOBUS, is a protocol that specifies a serial data network for control and communications on forestry or agricultural tractors with mounted, semimounted, towed, or self-propelled implements. Based on the CANbus physical layer, ISO 11783 standardizes the method and format of data transfer between sensors, actuators, control elements, information storage, and display units that are mounted on or part of the tractor.

Precision farming is a well-known ISOBUS application (see Figure 1). The international Agricultural Industry Electronics Foundation (AEF) focuses the resources and knowledge of its members, such as AGCO and John Deere, toward enhancing the use of electronics in the farming sector. AEF has addressed important subjects surrounding ISOBUS and control system safety.

Figure 1: SFF-controlled farming equipment uses ISOBUS electronics to automate system functions and standardize system communications.
(Click graphic to zoom by 1.9x)

The SAE J1939 protocol, a CANbus variant for trucks and buses, has many parts in common with ISO 11783 to provide maximum interoperability. The Competence Center ISOBUS (CCI) is a German organization that promotes this technology (see Figure 2). Jetter, an industrial and mobile automation solutions provider, and Krone, a farming equipment manufacturer, are members of CCI.

Figure 2: The Competence Center ISOBUS promotes the CCI ISOBUS HMI terminal and other technologies for controlling agricultural machinery.
(Click graphic to zoom by 1.9x)

Krone makes a large selection of farming machinery such as self-propelled mowers. The Krone Big M features constant power, crop-cutting discs, protection from rocks and foreign objects, and humidity sensing under the control of a Small Form Factor (SFF)-based system. The SFF boards are enclosed in rugged aluminum boxes protected up to IP68 for a temperature range of -40 °C to +85 °C.

This system uses MCUs like the JCM-350 from Jetter. A 32-bit ColdFire microprocessor coordinates two CAN buses (ISOBUS), an SPI master, I2C, optional Ethernet and digital, as well as analog I/O. Jetter also provides matching software such as ISO-Designer, which is a mask editor for ISOBUS applications, the JetViewSoft visualization tool for HMI, and the JetSym STX language. ISOBUS specifies that data for the HMI masks (parameters) should be held in the peripheral (virtual terminal), not in the control computer. At power-up or first contact, the HMI control panel system loads the masks of all attached devices for operation. Preconfiguration and preloading are not required in such an environment. A random selection of peripherals can be used any time without specific configuration.

Summer events

The Boards & Solutions Conference on July 15 in Munich provided technology sessions on open standards and SFF boards. I presented the SFF overview and moderated the SFF technical trends forum. The afternoon session was divided into three tracks: industrial automation, medical electronics, and transportation electronics. Another major topic of discussion was how to ensure safe, reliable SFF performance for several years of continuous operation.

The Automatica conference and exhibition is held biannually in Munich, this year from June 8-11. It is considered to be the world’s largest trade show for robotics and automation technologies. About 31,000 visitors from 114 countries came to see products from more than 700 exhibitors.

For more information, contact Hermann at