safety remote controls
Hand-Held Safety Controllers
A range of 1-speed and 2-speed controllers from 4-button to 12-button. Some models have the option of
additional toggle switches and buttons, and data-feedback is available on one model. While many are used
on cranes, these controls have a huge number of applications in all types of hydraulic and electric machines -
both AC and DC.
Joystick Safety Controllers - Single Speed
A range of on-off (non-proportional) controllers which can use joysticks, pushbuttons and toggle switches for
control. Typical applications are concrete-pumps, small EWPs, and other hydraulic machines with non-
proportional control.
Joystick Safety Controllers - Multi-Speed
Typically used on overhead cranes, these remote controls feature joysticks with multi-step functions - up to 6
speeds available. There are models for simple cranes, through to large and complex magnet cranes.
Fully Proportional Safety Controllers
Most commonly used on hydraulic machines, these controllers can be used on both proportional and on-off
systems, and there are many models and options. Extremely configurable, these systems can be used for the
simplest application, through to complex tunnelling machines.
What is a safety remote control?
Safety remote controls are specially designed for the control of potentially hazardous machinery - for example cranes and hoists, concrete pumps,
container side-lifters, elevating work platforms, and many others. Safety remote controls are necessary where the failure of the system (e.g. a command
turning on unexpectedly, or the STOP failing to operate) could pose a risk of injury or death, or of damage to the machine or other property.
Safety remote controls include many special features that increase Functional Safety by increasing the fault-tolerance of the
systems. Safety remote controls share little in common with general-purpose remote controls (such as door openers) which do not fail-to-safety.
Different applications require different levels of Functional Safety, and various Standards define different categories and performance levels that
are sometimes mandated for specific machine types.
Safety remote controls must contain specific design features to meet these strict requirements. Amongst these are:
- Dual redundant input devices (e.g. joysticks)
- Dual redundant output devices (e.g. relays)
- Redundant and self-monitoring encoders and decoders
- Tamperproof and guaranteed unique addressing systems
- Active and passive STOP systems
- High-reliability radio links with frequency management
These issues are fully discussed in our white paper on Functional Safety in remote control systems, which is recommended reading for anyone
considering the application of radio remote controls to machines.
Types of safety remote control
When selecting a radio remote control for a machine, the best approach is to consider the application firstly from the operator’s perspective:
- What form-factor is appropriate? A hand-held controller, or a “belly-box” (a controller worn around the waist)?
- What actuators suit the commands that must be given? The available choices, depending on the model of controller, include
- single-speed pushbuttons
- 2-speed pushbuttons
- Single-speed joysticks (on-off types)
- Multispeed joysticks (up to 5 or 6 steps)- typically used on cranes
- Fully proportional joysticks- typically used on hydraulic machinery, but also on variable-speed drives
- Toggle switches in latching/momentary types
- Potentiometers (so-called “pots”) typically used to allow a knob to control the speed of an operation.
The design of the machine will also influence the choice of controller, and of the receiver. Considerations include the power supply available, the load being
switched, the available space for the installation, and the types of control devices (contactors, valves, solenoids, etc) being operated. If there is a programmable
controller on the machine, the receiver and the PLC can communicate over CANOpen with either the receiver, the PLC, or both being responsible for control of
the machine elements.
Our engineers are widely experienced in many types of machinery, and can help you make the correct decision from the beginning. Please contact us to discuss
your application, or for any advice required.
Machine-to-Machine Safety Controllers
The transmitter in these systems is not carried by an operator, but typically embedded in a machine control
panel. This allows for safe real-time communication between machines, or to radio-enable a conventional
fixed control-panel.