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CANOpen

Laird Technologies CANopen Remote Control is made with safety and productivity in mind and it sets new standards for the industry. It is part of the new CattronControl products family. This CANopen Mining LHD system greatly simplifies the installation of a remote control on any CAN-based vehicle. When connected to a CAN network of the vehicle’s main computer or PLC, the Machine Control Unit (MCU) acts as a wireless gateway between the vehicle and the Operator Control Unit (OCU). All functions executed on the OCU are transferred on the CAN Network and vehicle vital signs are transmitted back to the OCU.

The system consists of two major components: the OCU, held by the operator, and the MCU, located on the vehicle to control. The system allows an operator to remotely control a CANopen LHD through a RF link.

The RF link provides two-way data transmission between the OCU and the MCU. RF telegrams are transmitted with the following characteristics:

  • Telegram transmission rate: 80msec (configurable)
  • Each telegram contains the complete set of OCU command values.
  • RF telegrams are protected against corruption with mechanisms such as CRC, sequencing, etc.

The system is compatible with several Laird Technologies RF modules, each supporting a particular frequency band. RF channel can be pre-configured in Transkey configuration device (more details in next section), or selected by the operator.

Contact Laird Technologies today for your complete application solutions. 

The OCU (Operator Control Unit)

The OCU is the interface to the operator. Each OCU can be custom engineered at our factory to meet specific customer’s needs. It comes in two different formats (Medium and Large Format).

The Medium format, LRC-M1, can accommodate up to two joysticks plus several types of push buttons and toggle switches. The Large format, LRC-L1, can accommodate up to four joysticks and can accommodate even more types of push buttons and toggle switches.

It is designed to withstand tough mining environments which may include humidity, oil, vibrations, and drastic differences in temperature. The OCU has the following features:

  • Power switch – Key-type switch, used to power on and off the unit. The power switch circuit has a delayed shut-off feature; when the switch is turned to OFF position, the OCU remains powered and transmitting for 30sec before it shuts off completely. During this delayed shut-off period, only the STOP switch remains operational.
  • STOP switch – Mushroom-type switch, with two sets of contacts for increased safety.
  • Operating Elements – Set of push buttons, toggle switches and joysticks used to send action commands to the machine.
  • LED display – 5 bicolor LEDs are used to display operating status, errors, etc.
  • LCD display – Feedback information from the machine can be displayed on the LCD like hydraulic pressure and engine temperature.
  • Battery monitoring – Provides detection and indication of low battery condition. The unit automatically powers-off if battery voltage becomes lower than safe operation threshold.
  • Tilt sensing – Provides detection of excessive OCU tilt. The detection angled is programmable.

The OCU is powered by re-chargeable 4.8 V, 1600 mAh, Nickel Metal Hydride (Ni-MH) battery pack. An optional Battery Housing is available which holds two Type C Alkaline Batteries.

The MCU (Machine Control Unit)

The MCU is the interface to the machine. It is enclosed in compact, watertight, impact resistant black nylon housing. The main connector is integrated to the front plate, ensuring sealed packaging. The main connector is PCB mounted, so there is no harness inside the housing, except for the RF cable. External dimensions (including connectors) are 145 x 138 x 48mm.

The MCU main features are:

  • Dual CANbus interfaces – The CANbus interfaces run CANopen protocol, slave operation. The CANopen interfaces meet ISO11898-2 standard. They are electrically isolated.
  • Dual safety relays outputs – The MCU provide two monitored safety relays (forcibly guided contact relays, according to EN50205). The normally-opened contacts close when a valid RF link is present between the OCU and MCU, and both OCU and MCU are operating without any error. The safety relays can be used as STOP devices independent of the CANopen link.
  • LED display – 5 bicolor LEDs are provided to display operating status and errors.

The CANOpen Protocol

CANopen is a standardized protocol. CANopen operation for the actual implementation is summarized below:

  • The MCU operates as a CANopen NMT slave with fixed NodeID (010h) and fixed baud rate (250kbps).
  • CANopen operation state is independent from the RF connection status.
  • The CANopen interface provides the value of all commands from the OCU through PDO frames. All available PDOs are sent each time a new RF telegram is received, or after a 250msec delay, depending on which event occurs first.
  • If the MCU is idle (before a connection, after active STOP, after passive STOP), all commands are reset to their safe values (zero).
  • CAN LEDs behavior conforms to CiA DR303-3.

Dual Channel Redundant Architecture for Saftey

In order to meet the requirements for safety-critical applications, a dual channel redundant architecture is implemented on both OCU and MCU. Both units have two processors: a Master processor and a Slave processor. The two processors perform similar operations on process data, and compare their results at specific check points in the process. If any inconsistency between the two processors is detected, or if any processor detects a failure, an error is declared and the system stops.

Literature

CANOpen Brochure
Road Header Brochure
Surface Drill Brochure 

 

Technical Data & Specifications

RF 

Frequency  Ranges 335 MHz
418-419 MHz
433-434 MHz
447 MHz
470 MHz
868-869 MHz
903-927 MHz
Transmission Speed 4.8 - 20 Kbits/s
Transmitter Output Power

<10 mW

Receiver Sensitivity

-107 dBm

Electronics 

Digital Circuitry Dual-processor technology
System Addresses 24 Bit = 16 million addresses


CAN Interface Characteristics 

CAN Format CAN 2.0A and CAN 2.0B
Bus Speed 4.8 - 20 Kbits/s
Standard

110, 20, 50, 125, 250, 500, 1000 kbps

Protection

Exceeds ISO 11898-2
Bus fault protection ( -27 to +40 V)
Transient voltage (-200 to +200 V)