CAN connection is key


Kathrin Peters, marketing manager with Griessbach – a leader in bespoke HMI solutions – explores how industrial vehicle manufacturers are increasingly turning to network-enabled pushbutton modules to control peripheral machine functions

Since conventional flip switches offer limited functionality – only two switching states and no diagnostics – and their installation with one-by-one wiring is time-consuming, more and more manufacturers of industrial, construction, and agricultural vehicles prefer networkable alternatives. The German HMI specialist Griessbach answers this increased demand by expanding its portfolio of bus-enabled CAN modules with four to 12 short-stroke keys, adding two new series with additional options.

Turnkey input units

The keypads are fully wired and ready for connection. They feature CANopen and J1939 interfaces and can be configured as required for baud rate, addressing, terminating resistor and front foil design. Their optimised hardware architecture with a more powerful 32-bit controller and a larger memory allows for the implementation of customised protocols and optional safety protocols. Robust Deutsch plug connectors fed in from below are resin-molded with the entire assembly inside the housing; they secure the connection against mechanical stress caused by shock and vibration. Full resin casting ensures IP65 protection.

New standard models

Griessbach now offers two new off-the-shelf series of CAN modules with four, six, eight, ten or 12 pushbuttons to suit different requirements and budgets. Pushbutton icons on the Basic version are backlit by white LEDs, in addition to two green status LEDs above individual keys. The pushbuttons on Pro modules feature ring lighting in traffic light colors with optional color change; RGB LEDs enable individual icon lighting in freely selectable colors. Thanks to a remote wake-up function, Pro-series modules can be activated from power-saving mode to functional state via a CAN request. The integrated error memory logs any instances of malfunctions.

Griessbach is working on developing a third version, the Safety-Plus product line with a dedicated safety controller supporting redundant configuration of individual keys. These modules will feature pushbuttons with icons with white LED backlights as well as three signal LEDs per keypad. Due to their high diagnostic coverage, they meet PL-c safety requirements. All three product lines are enabled for diagnostics and qualify for additional customisation, which the manufacturer will realise on request.

Versatile configuration, intuitive use

A large agricultural vehicle manufacturer purchases customised plug & play keypads for decentralised control of various machine functions from Griessbach. The keypads with four and six pushbuttons minimise the wiring effort for establishing the bus connection. Griessbach supplies them as ready-to-install modules with an onboard boot loader for software updates and functional enhancements. Due to the generic J1939 interface, the keypads do not need to be physically adapted to different machine types and functions. Backlit, function-specific icons enable intuitive operation even in twilight and at night.

CAN do

An international manufacturer of sewer cleaning vehicles also uses CAN modules for user guidance by light. The keypads installed in the rear terminal are lit in different colours that signify different function blocks. Function-specific lighting and a homogeneous design with universally intelligible pictograms ensure operating safety. For easy orientation, keys are blacked out when their function is not available in the selected setting. The CAN standard modules also allow shortcuts to machine control functions.

A leading German machine and vehicle manufacturer integrates three customised CAN modules in some mobile chipper models. Operators can configure the 16 keys via the machine control touchscreen by choosing from over 100 options. Another application example is a bitumen paver: the driver can individually control nozzles for primers, bitumen, and binders via 12-key CAN modules. The CAN modules are also used for temperature-controlled switching of the paver’s gas burner system.

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About Author


Saul Wordsworth is deputy editor of the iVT brand - which includes digital and print editions of a quarterly magazine and Off-Highway Annual, as well as He is a keen cyclist and lives in north London.

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