Terms: Brief Explanation of the Various TALK/LISTEN Button Options

A Brief Explanation of the Various TALK / LISTEN Button Options  for Belt Packs, I-Stations and v-panel buttons
Terms: A port can be any panel, 4wire, external device, beltpack, partyline or group.
Mechanical key press:
MOMENTARY:  (Also known as PUSH-TO-TALK) By pressing and holding the button for the duration of time it is engaged, you “open” the audio path. When you let go, you “close” the audio path. 
LATCHING: By tapping the button, you “open” the audio path and to close, tap again. 

Audio key functions.
TALK: When you push the button, you talk to the selected port but there is no “listen” function. 
LISTEN: When you push the button, you can hear the port, but not “talk” to it. 
TALK & LISTEN: When you push the button, you can both TALK and LISTEN to that port, but when you unlatch or take your finger off the button, both TALK and LISTEN go away. 
DUAL TALK & LISTEN:  By tapping the button, you latch the “listen” on. To ”talk” to the port, you press &  hold the button, then let go to stop “talking”. You can’t latch both the “talk” and “listen” in this mode…only the “listen” To stop listening - tap the button again to "un-latch"
TALK with a FORCED LISTEN:The “listen” is always on. (To turn it down or off, - adjust the crosspoint level -on your panel or beltpack.) You can either latch or push-to-talk (momentary) your “talk” function. This is the most common scheme used for Party Lines, as it emulates the two-wire environment.