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The Fight for the Cab

Cab Monitors are going through an extensive streamlining. This year TeeJet, Dickey-john and the Big 4 tractor makers — AGCO, New Holland, Case IH and John Deere — all introduced new or upgraded versions of virtual terminals (VTs) for use in tractors.

VTs make it possible to view (and in some cases control) not only tractor functions but also implement functions, regardless of brand, from a single monitor. In the past, as many as six monitors may have been required to do the same functions. This upgrade has been made possible by an electronic communications standard called ISO 11783, commonly called ISOBUS.

“The goal of the ISO standard is to allow single point control of all implements from one monitor in the cab called a virtual terminal,” says Rich Gould, vice president of TeeJet Technologies. “Tractors will ultimately have just one monitor instead of multiple devices to control planters, sprayers, spreaders and other implements.”

Experts say this offering will be a win for buyers. But it also brings to bear some questions, such as: What functions should a VT control? And will it replace the need for aftermarket display screens?

These questions are fueling a battle for the cab as manufacturers duke it out to retain display space and operating control of your tractor and implement functions.

That battle began with the advent of electronic controllers on implements and tractors. In the early 1990s, companies started to convert mechanical functions to electromechanical or electrohydraulic controls. Engineers put motors, circuits and wires onto valves and other components so operators could control functions from the cab rather than having to get out of the seat to move a lever.

While electronics added convenience, they also added clutter. Each electronic function required its own monitor, wiring harness and electronic control unit (ECU), called the “black box” or “brains,” which blocked visibility. Marvin Stone, a professor at Oklahoma State University, coined the term “monitor wallpaper” to describe the array of displays and peripherals that were lining the A-posts and glass in tractor cabs.

Then, later in the '90s, an automotive standard called Controller Area Network (CAN) was used to reduce the amount of hardware required. CAN technology enabled engineers to network electronic devices using a single group of wires called a serial “bus.”

However, while CAN Bus consolidated hardware, it still didn't eliminate it because each company used proprietary messaging and only same-brand components could be hardwired together. “We had our system, Deere, Case IH and New Holland had theirs, and none of them could cross data back and forth,” says Wade Stewart, product manager with AutoFarm who worked for AGCO at the time he was interviewed for this story. Farmers who used different brands of electronics were still stuck with multiple peripherals and wiring harnesses that would have to be fished out the back window to reach the implement.

Observers say the problem was analogous to adoption of hydraulics 40 or 50 years ago before the industry agreed to a standard hydraulic connection that made it easy to connect one brand of implement to different brands of tractors.

In 2000, machinery manufacturers agreed to implement a similar standard for electrical connections. The standard, called ISO 11783 or ISOBUS, is based on the CAN Bus system. It originated in Europe, where mixed fleets on farms are common due to the high number of short-line companies. In Europe, ISOBUS equipment has been readily available for at least the past three years.

Adoption here in the U.S. has been slower. “Trying to get everyone to agree on the standard is like trying to part the Red Sea,” says AutoFarm's Stewart. “Our meetings have been compared to the United Nations'.”

In 2002, the North American ISOBUS Implementation Taskforce (NAIITF ) was formed to promote the industry's adoption of the standard. William Rudolph, NAIITF's general chair, says the standard has been in published, usable form for the last four years. Some parts are still being revised.

Who's compliant?

“Under the standard, any ISOBUS-compliant implement from any manufacturer can be displayed and controlled using the built-in user terminal that comes with the ISOBUS-compliant tractor,” Rudolph says. Compliance is determined by an independent testing lab appointed by NAIITF.

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Companies practice for the test by attending “Plug Fests,” which are informal demonstrations of connectability between different manufacturers' devices. Connection is made through a standard plug called a “breakaway connector.”

To date, all four of the major original equipment manufacturers (OEMs) have active ISOBUS development programs and have introduced ISO-compliant products. (For a partial listing of ISOBUS-compliant devices, visit Rudolph says the major electronics suppliers are also heavily involved in ISOBUS development in order to remain competitive.

Resistance, he says, has been mostly from second-tier equipment manufacturers for two reasons. “First there have not been a lot of tractors equipped with ISOBUS until just recently, so there has not been a need for second-tier manufacturers to invest in ISOBUS development,” he says. “Secondly, public awareness of the technology is low, so there has been little demand from customers.” He expects both issues to dissolve as more equipment comes standard-equipped with ISOBUS technology.

Not playing fair?

The electronics manufacturers see two problems with adopting the ISOBUS standard as currently written. “One of the problems we face in North America is that not everyone is willing to play nice with each other,” says David King, marketing manager for Ag Leader. “While companies promote that they meet the ISOBUS standard, not everybody's ISO equipment can be read by everybody's VT.”

King says some OEMs that market themselves as ISO-complaint are still using language that only their brand of equipment can understand to control certain functions, namely steering and vehicle functions.

Deane Malott, director of marketing for AutoFarm, agrees: “The true concept of the ISO standard is that I should be able to take any task controller and plug it into any VT. The problem is, vendors are only halfway committed to that vision by keeping some functions proprietary.”

OEMs counter by saying that opening up their vehicle functions to third-party controllers is a liability risk they are not willing to take. “Machine control is core to our product and is not something we are going to give up,” says Kirk Wesley, Advanced Farming Systems global manager with Case IH. “Other companies can provide steering and implement functions, but we are not going to give them the code or ability to reach into our vehicles and change engine rpm, hydraulics or other settings that could put a tractor out of spec.”

A second reported problem is that the ISOBUS standard does not cover or support all of the functions that can be monitored and controlled by third-party controllers. This limits what aftermarket companies that make third-party controllers can offer under the ISOBUS standard.

“The VT can only recognize those functions that have been defined by the ISO standard, unless the VT has been programmed to display those functions,” Ag Leader's King says. “Some farmers are going to want more than what is provided in the ISOBUS protocol.”

Graphic limitations

Two functions that are still being defined under the standard are graphics and moving maps. According to Marlin Melander, marketing manager for Raven Industries, a VT is divided into four quadrants to show a lot of information at the same time. “Some of those windows are going to be fairly small,” Melander says. “So while VTs work fine for showing digital or numeric information such as rates being applied, most VTs do not have processors or graphics accelerators to be able to show maps.”

George Huber, global sales manager with Trimble Agricultural Division, says another limitation of the ISO 11783 protocol is message latency. “Some messages, such as GPS, are highly time critical,” he says. The standard does not ensure that the GPS signal is placed in the front of the messaging stream.

Two displays for now?

Because of these problems, some aftermarket companies say that growers who want the broadest range in task controllers may have to settle for a second display in the cab until the standard catches up with growers' needs. That could take another three to five years, says AutoFarm's Malott.

He predicts that, if and when the industry arrives at a single display that can do all functions, aftermarket companies will find their niche in building controllers that work off that one display. “In the end, it will be a competition among task controllers if everything plays out in the best interest of growers,” he says. “And the terminal will be just another device that is built into the tractor to provide the interface for those controllers.”

OEMs maintain that a one-display solution is possible, especially as the technology advances and is able to incorporate more functions at a lower cost. Matt Danner of John Deere says, “ISOBUS electronic compatibility is comparable to what Pioneer hydraulic couplers were 20 years ago, and look at the difference that made in the industry.”

AGCO Corporation GTA Console Iand GTA Console II

The GTA Console I comes standard on Challenger MT600B series tractors and is an option on the newest generations of Challenger MT500B, AGCO RT/DT and Massey Ferguson 7400/8400 series tractors. It is used to control numerous tractor functions as well as ISO-compliant implements such as non-variable-rate planters, round balers and big balers.

The GTA Console II oversees functions in Challenger, Gleaner and Massey Ferguson Class VIII combines and offers yield monitoring with Fieldstar II in all new Class VI, VII and VIII combines. It has capabilities for variable-rate planting and is an option on RoGator, TerraGator and Spra-Coupe application equipment.

Both consoles integrate with AutoGuide on vehicles with this option. Fendt's Vario VT comes standard on high-horsepower tractors. AGCO's VT is not sold as a stand-alone unit. Contact your AGCO dealer, call 888/989-8525, visit, or circle 101.

Case IH AFS Pro 600

The AFS Pro 600 has a color touch-screen display and is used with the AFS AccuGuide system. It handles yield monitoring and mapping tasks on 2100, 2300 and 2500 series combines and handles those precision operations along with vehicle functions on Axial-Flow 7010 and 8010 combines. The AFS Pro 600 display will perform planter functions and control prescription variable seed planting on Case IH 1200 and 1250 series ASM pull-type planters. It comes standard or optional, depending on the model, with the Case IH 1200 series planters. On Case IH Magnum, Steiger and Puma tractors, the AFS Pro 600 is an optional item providing machine function and AFS AccuGuide technology.

Suggested list price: around $5,000 when sold as an option. Contact your local Case IH dealer, call 262/636-6011, visit, or circle 102.

John Deere GreenStar2 system

The GreenStar2 system includes a color display option, the GreenStar 2600, which can be used with most tractors and implements. The display comes standard with GreenStar Basics software that includes an established set of features necessary for manual guidance and documentation for tillage, seeding, crop care and harvest. The system can be upgraded with Pro Modules or AutoTrac for advanced functionality.

Suggested list price: $5,000. Contact your local John Deere dealer, call 866/993-3373, visit, or circle 103.

New Holland IntelliView II and IntelliView Plus II

The IntelliView II display monitor is mounted on the right-hand armrest of all models equipped with New Holland's IntelliSteer autosteering system. The operator has easy fingertip control of calibrations, data storage control and operational functions. IntelliView Plus II (shown) runs the combine or tractor by monitoring critical machine functions and provides the interface for the IntelliSteer autosteering system. It is available on New Holland CR9000 series Twin Rotor combines, CX8000 Series super-conventional combines and TJ series II and TG series II tractors.

The IntelliView II display is a standard feature and the IntelliView Plus II is a $4,800 (retail pricing) option. Contact New Holland North America at 888/290-7377, visit, or circle 104.

Dickey-john IntelliAg

The IntelliAg delivers planting and granular fertilizer application control. It features a monitor and either a planter/grain drill control or air cart control module, which can function on any manufacturer's equipment. Modules offer four control channels, which accept input from hopper level sensors, shaft rpm sensors, ground speed sensors, implement switches and seed sensors.

Suggested retail price: $3,200. Contact Dickey-john at 800/637-2952,, or circle 105.

TeeJet PowerLink 640

The PowerLink 640 provides a standards-based user interface for any ISOBUS implement control. The ISOBUS standard calls for a universal interface for multiple implement controls. TeeJet PowerLink 640 is designed for compatibility with many TeeJet and third-party job computers.

Suggested list price: $3,900. Contact: Spraying Systems Company at 217/753-8424,, or circle 106.

For a partial listing of other ISOBUS-compliant devices, visit


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