Wikipedia
AMX used to manufacture the Axcent range of controllers, computing devices designed to be used to control other devices, typically in an Audio-Visual control system. They have now been superseded by the NetLinx controller range.
An example was the "Axcent3 Integrated Axcess Controller" which had 6 RS-232/RS-485 serial ports, 8 Relays, 6 Infrared/Serial ports and 6 Input/Outputs. Serial ports can send and receive serial strings, typically ASCII instructions and replies. Relays permit switching of modest currents. IR ports can send Infrared signals which emulate typical remote control devices that control (for instance) Televisions and VCRs. Input/output ports detect contact closures.
AMX supplies an IDE known as NetLinx Studio which allows a proprietary language to be edited, compiled and sent to the Axcent controller. The name of this language is AXCESS.
Powerful Axcent controllers are readily available on eBay for prices vastly lower than comparable new NetLinx controllers. It is easy to build a fully NetLinx-programmed system using a small NetLinx controller linked to one or more Axcent controllers.