KRS Drive Systems SIL2 Rated Intelligent Footswitch Control Unit
For Both AC & DC Shuttle Cars
Utilising Hall Effect Shaft Positioning Encoder which has an operational life of 50 million actuations.
Our second generation Footswitch control unit is used as the accelerator unit for Traction Motor Drive Systems which are incorporated into mining vehicles such as shuttle cars.
KRS Drive Systems is the Australian Agent for Cableform Inc which designs and builds specialist Digital D.C. Drive Systems for Traction applications, Industrial Machinery including DC Cranes, Magnet Controls and Locomotive Controls.
The Footswitch can also be incorporated into other make drive systems using different software. For example a Saminco Drive unit that requires a control voltage of 0V to 4V DC input.
Our Footswitch unit is intelligent, with on board microchip that generates all the necessary outputs to drive the machine when the Footswitch is actuated by the driver.
The KRS Footswitch offers a higher level of integrity than previously found on older types of footswitch units.
KRS Footswitch Description
The Hall Effect Transducer has an operational life of up to 50 million actuations as compared to a normal resistance potentiometers currently used, which only have an operational life of less than 1 million actuations.
The Foot Switch features intelligent software to monitor the limit switches and Hall Effect Sensor and then in turn, outputs the correct signals to the Drive system and the shuttle car electrics. If an error is detected the software will disable the outputs which in turn will stop the vehicle.
The Electronic hardware also has a micro monitor watch dog system which checks the health of the microchip and the program running inside it. There is also a power up check that is carried out, that will disable all the outputs if the software finds an error in the footswitch or if it is not in the neutral position. The software will disable all the outputs (Forward, Reverse, Neutral and the Analogue Control Output) from the footswitch.
Also featured within the Footswitch is an Optional serial port which allows the end user to interface directly with the vehicle’s controller PLC if available. This then allows the user more information for a higher level of diagnostic capability than before.
The Footswitch unit is packaged complete with the mechanical arrangement so that it can be installed directly into most existing enclosures found on typical underground mining machines and is also easily integrated into above ground machinery requiring this type of control.
The internal centering spring automatically returns the footswitch to the neutral position when the operation force is removed. The centering spring works in conjunction with external centering springs and linkages found on most shuttle cars.
KRS Footswitch SIL Summary Data
Architectural SIL Claim Limit (SILCL) = SIL2
Probability of Dangerous Failure Per Hour (PFH) = 5.7 x 10-7
(assumes proof-test / inspection interval of three (3) months or less).
A detailed report is available.
KRS-10-01-A Rev.1(23rd March 2010): KRS Technologies Pty. Ltd. - Intelligent Footswitch Control Unit -
Failure Modes, Effects and Diagnostic Analysis (FMEDA), Safe Failure Fraction (SFF) and Probability of Dangerous Failure Calculation.
Author: Marcus Punch Pty. Ltd.
KRS Footswitch Specifications
Power Supply Requirements - 24VDC +/- 10% @ 100mA
Operating Temperature Range - 0 to 60 Deg C
Relay Output Contact Ratings - 5A @ 240V AC Max
Analogue Output - Isolated +3.5V - 0V DC - Cableform System
Analogue Output - Isolated 0 – +4.0 V DC – Saminco System
Analogue Output Isolation - 1500V DC
Shaft Angle position Sensor - Hall Effect Device – 50 Million Operations
Back up Limit Switches - > 5 Million Operations @ 5VDC / 5mA
Control Method - Proprietary Micro Controller & Software.
Software Protection - Hardware watch dog protection
Optional Serial Port - RS 485 – Consult Factory
Dimensions - See Dimensional details
Weight - Approx. 1 Kg