Pendant stations are sophisticated, handheld terminals that are used to control robot or machine movements from point to point, within a determined space. They consist of a hanging control console furnished with joysticks, push-buttons or rotary cam switches. A type of industrial control pendant, teach pendants are the most popular robotics teaching method, and are used widely with all types of robots, in many industries. As the robot moves within this determined space, the various points are recorded into its memory banks, and can be located later on through subsequent playback. There are a number of teach pendant types available, depending on the type of application for which they will be used. If the goal is simply to monitor and control a robotics unit, then a simple control box style is suitable. If additional capabilities, such as on the fly programming are required, more sophisticated boxes should be used.
Pendant stations are equipped with switches, dials, and pushbuttons through which data is relayed to the robotics unit, and additional monitoring systems if necessary. The relationship between industrial control pendants and their subservient unit is generally established via an interconnected cabling system. However, more advanced wireless devices are available.
During use, the operator actuates the switches on manual pendants in a specific order. This in turn causes the robot, end effector, or machine, to move to and from the desired points. As the end effector reaches the desired point, the operator uses the record push-button to enter the location into the robot, or robot controller’s memory banks. This is the most common programming method for playback robots.
The usage of pendant stations is common, however it has a significant disadvantage in that the operator must divert his/her attention away from the movement of the machine during programming in order to locate the appropriate pushbutton to move the robot. The use of a joystick provides a solution to this problem as the movement of the stick in a certain direction propels the robot or machine in that direction. This option is available on more advanced pendant station types.