| Cam
| A rotating or sliding piece that imparts motion to, or receives motion from, a roller moving against its edge. |
| Indicating Light
| Also known as pilot lights. Lights on a panel that show if a control circuit or power circuit is energized, or show the state of the logic in the circuitry. |
| IP
| Ingress Protection. European environmental ratings similar to USA NEMA ratings. |
| IEC
| The International Electro-technical Commission. With headquarters in Geneva, Switzerland, it is associated with equipment used internationally. IEC devices are built with materials required for specific applications. |
| Maintained
| The circuit remains closed after pressure is released from the button. |
| Momentary
| The closed circuit lasts only as long as pressure is maintained on the button. |
| NEMA
| National Electrical Manufacturers Association. This group has ratings of an enclosure's ability to provide a degree of protection against contact with equipment and against specified environmental conditions. |
| Potentiometer
| A dial that adjusts the amount of voltage sent to a machine. |
| Pushbutton
| (A) The operative force that either opens or closes an electrical circuit. (B) The button assembly you push on a panel. (C) Indicating lights, selector switches, potentiometers—and pushbuttons—through which people interact with machines. |
| Pushbutton Station
| One or more pushbuttons in a common enclosure. |
| Selector Switch
| An operator which is mechanically linked to one or more contacts and which makes or breaks the contacts when rotated to two or more positions. |
| Stacklight
| A mini-tower of independent, colored lights providing 360° visual and/or audible indication of machine faults, low part levels, etc. |
| UL
| Underwriter's Laboratories, Inc. A non-profit organization that establishes, maintains and operates laboratories for the examination and testing of devices, systems and materials, primarily for safety. |
