Iwatsu ENTERPROSE-CS Owner's Manual page 228

Multi-Line
(Up to 3 outside & 1 inside parties)
While speaking on an outside call:
 Press and release the receiver button quickly or press the Flash key.
 Dial the Exclusive Hold code
 Press and release the receiver button quickly or press the Flash key.
 Dial the second outside party.
 Wait for the second party to answer.
 Press and release the receiver button.
 Dial the Conference Code
To add the 3rd outside line, repeat the same procedure.
(Polycom SIP Station)
 Press the Hold soft key.
 Dial the Exclusive Hold code
 Hang up.
 Dial the second outside party.
 Press the Hold soft key.
 Dial the Conference Code
Trunk-to-Trunk
(Up to 2 outside parties)
When you are speaking with two outside parties in a Multi-line Conference
call and wish to leave the call:
 Press and release the receiver button quickly or press the Flash key.
 Dial the Conference code
 Hang up.
(Polycom SIP Station):
 Press the Hold soft key.
 Dial the Conference code
 Hang up.
To get back in the Multi-line Conference:
 Lift the receiver.
SIP & SINGLE LINE TELEPHONE USER GUIDE - 210
.

and all parties will be connected.
.

and all parties will be connected.
.
.