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By Chris Hunsaker, Co- Founder / CEO at Acuitus Ag and guest panelist at the 2023 Marketing & Distribution Convention.

This article continues a series where we’ll explore different aspects of technology and how they might shape the future of ag machinery.

In the 1960s, while Gordon Moore was advancing semiconductors, another development was taking place in industry. For decades, factory machines had been controlled via electromechanical relays (mechanical linkages, buttons, switches, coils, and lots of wire). This system became complicated as machines became more sophisticated. All logic in how the relays interacted with each other had to be built into the actual wiring and hardware of the system (called ladder logic). Any change in the behavior of a particular system required it to be rewired. The more complex the system, the harder it was to service, too.

In 1968, General Motors began work on a relay system replacement in their factories using a simple computer to mimic the ladder logic of the physical system with software. By 1969 (ironically the same year the $200,000 Apollo Guidance Computer put man on the moon), the Programmable Logic Controller (PLC) was born and GM started using them in manufacturing. PLC compute power was limited, but this wasn’t a problem because they performed simple tasks.

PLCs first appeared in automobiles in the 1970s, first to control the engine and then to control other functions. The approach was the same–replace physical control systems with computers to mimic physical system functions. Simple PLCs required simple software. Proprietary PLC software was created by PLC manufacturers focused on the reliability, security, and safety of the system. In off-highway vehicles (like construction, mining, and agriculture), use of PLCs followed trends from industry and automotive, with much of the hardware and related software being adapted from those applications.

As use of PLCs in vehicles grew, so did the need for a communication protocol standard for data transfer between PLCs. In the mid 1980s, Bosch engineers in Germany created the Controller Area Network bus (CAN bus) to standardize and simplify communication between PLCs in automobiles. The protocol was swiftly adopted in automotive applications because it was robust, handled real-time data transfer reliably, and reduced the amount of wiring needed to connect different vehicle systems.

CAN Bus use began in agriculture in the 1990s, first on tractors and then on implements via the ISO 11783 standard. The ag-specific implementation, dubbed ISOBUS, envisioned integrated tractors and implements. Twenty five years later, much of that vision remains unrealized. In the next article, we’ll explore why.

Come see me in Little Rock at the Supplier Showcase at booth # 39 or reach out at either chris@acuitusag.com or (208)243-0135!

| Member since 2023