The lamps on a phone device can be lit in a variety of different lighting modes. Unlike ringing patterns, lamp modes are more uniform across phone sets of different vendors. A common set of lamp modes is defined by the API. A lamp identified by its lamp-button identifier can be lit in a given lamp mode. A lamp can also be queried for its current lamp mode.
The TAPI functions used for lamps are phoneSetLamp, which lights a lamp on a specified open phone device in a given lamp lighting mode, and phoneGetLamp, which returns the current lamp mode of the specified lamp.
When a lamp of a phone device is changed, a PHONE_STATE message is sent to the application to notify the application about the state change. Parameters to this message provide an indication of the change.