Toa N-8000 Series - Manual (Page 604)

8-4
Chapter 8 APPENDIX
1.1.5. Half duplex conversation by way of PTT operation
When the PTT key is pressed, this permits
one-way conversation from the key-operated
station. Releasing the PTT key enables one-
way conversation from the other party.
When the PTT keys at both stations are
pressed simultaneously, the last key-operated
station takes precedence.
(Refer to p. 8-5, "PTT Conversation." )
PTT
One-way conversation
One-way conversation