Automotive Mobile Audio Video

If the future of off-highway power-trains is electronic control, which it certainly seems to be, and if the future of off-highway hydraulics will revolve around complete systems, then CAN-bus controllers are the right candidates to pull all the discrete components together as a true system.

CAN, or controller area network, systems were originally developed for use in the automotive world and have begun to find their way to the heavy-duty markets. With an international standard bus system for mobile applications, ISO 11898 in-place, there will be more, not fewer CAN-bus-controlled hydraulic systems in the future.

The Flo Draulic Group is marketing a CAN-bus system as a programmable controller that operates independently as a measuring, driving or controlling device for sensor-actuator management for off-highway hydraulic systems.

Targeted specifically at the off-highway equipment markets, especially agriculural, material handing, construction equipment, community/highway service and other various special vehicles, the ESX system is designed as a controller for the complete electrohydraulic system. This controller system works independently as a measuring, driving or controlling device for sensor-actuator management and is capable of executing a number of separate or related tasks in real time.

The heart of the system is an Infineon C167CR 16-bit, 20 MHz processor, with a CAN 2.0B interface, standard and extended formats, in low- or high-speed interfaces to 1 Mbit/sec. The processor has flash memory to 512 Kbytes, RAM to 256 Kbytes and EEPROM to 8 Kbytes. An RS232 interface is used that is programmable to a maximum 19200 baud rate. There are eight analog inputs, 16 digital/rpm inputs and 12 pulse width modulation (PWM)/digital outputs - eight at 4.0 amps, and four at 2.5 amps.

The ESX system was specifically designed for off-highway operating environments and can function from -40[degrees]F to + 187[degrees]F. The company said all inputs and outputs are protected against short circuit to ground or to voltage overload and have a built-in diagnostic capability.

Proportional valves can be driven without amplifiers or controller cards. The system can be programmed with PWM output with internal current measurement.

The controller is housed in a cast aluminum housing with a Gore-Tex breathing filter to provide a high degree of immunity from electromagnetic disturbances, moisture and also to protect against mechanical stresses. The standard controller housing has an IP65 rating, with IP67 available as an option.

Programming of the system can be done in high level "C" language or using an PLC graphical user interface (IEC 1131-3) with the following choice of languages: function block diagram; ladder diagram; instruction list; structured text; and sequential function chart. The function library, with ready-to-use function components, makes it possible to quickly program application software.

One of the keys to the ESX system said Bill Mauceri, vice president of Flo Draulic Inc, Norcross, Ga., is that all input and output channels of the controller are self-diagnostic and programmable by the end user. The system can detect short, or open circuits and a continuous internal diagnosis can be performed. A safety relay provides another means of switching off the digital and PWM outputs. The company also offers a line of software tools to read the error buffer, system diagnostics, visualization, and maintenance or repair services.

With the CAN interface, a number of ESX controllers can be integrated into a CAN network. Expansion of the ESX system can be accomplished via the two standard internal interfaces and various other modules to provide up to 12 additional input or output ports. This allows the system to be designed for specific customer applications.

Flo Draulic said using the ESX controllers can reduce costs for the lifetime of the machine, from production to service, while at the same time increasing the equipment's functionality.

# posted by Medical Information : 3:01 AM