Command giver
From a technical point of view, command transmitters are devices with which humans (the operator or operator) can influence a machine or system. The term control element is also often used.
variants
Command transmitters are available in a wide variety of designs, often as switches or buttons . All of them are related to the topic of “ man-machine interface ”. A sensible and intuitively understandable arrangement of the command devices is often considered under the heading of ergonomics .
Most command transmitters are now electrical or electronic, because they are usually inexpensive in this design. But there are also other auxiliary energies that can be used for this. Command transmitters can be pneumatic, hydraulic or mechanical.
Command transmitters can be classified according to the type of actuation, regardless of the auxiliary power used.
- Jog mode: The associated command is only effective as long as the command transmitter is pressed (actuated, held). Positioning tasks are typically solved with this.
- Touch mode: After activation, such a command device returns mechanically to the starting position. The operator can only recognize whether the command was effective based on reactions. A control lamp is often assigned for this purpose. Often times, when in doubt, keying is repeated.
- Switching operation
- Permanent influence
Command givers can also be classified according to the way in which the operator operates the command giver.
- by hand
- by foot
- with another part of the body
- There are special constructions for the physically handicapped (e.g. the eyes fixate a button).
Emergency stop switch
The decision to bring a machine or system into a safe state as quickly as possible must be possible for every person who is in the endangered area. The responsible commanders must therefore be recognizable for everyone. See kill switch .
Incorrect operation
While good accessibility should generally be guaranteed, problems often arise when command transmitters are operated carelessly or accidentally. There are different approaches to prevent these incorrect operations:
- In the case of fire alarms and smoke vents , a cover glass must usually be destroyed before actuation in order to prevent vandalism.
- Padlocks are used for unguarded machines or systems.
- Dangerous machines, such as chain saws , are protected from being switched on unintentionally by special constructions. For example, chainsaws have a throttle lock. This is unlocked by a second lever.
- With buttons, a cover flap prevents a command with major consequences from being triggered accidentally or unintentionally.
