OF5750/5950 Series January 2001 2 - 54FAX (OKIFAX 5750/5950 etc.)To ModemSWLineRemote controlAB2.9.2.6 Outline of Parallel Pick UpParallel pick up is a function that controls a fax (to make a fax in receive mode) from a tele-phone set connected parallel to a fax. The two possible parallel connections of telephone setsA and B are shown in the figure.Remote control: To control a fax from telephone set AParallel Pick Up (PP): To control a fax from telephone set B.• Why a PP function is needed !As shown in the block diagram on the next page, telephone sets B, A, A’ and A” are con-nected to a telephone line.Since A, A’ and A” are connected to the line via fax, off-hook status of any of the telephonesets can be detected by the OFF-HOOK Detector 16 in the block diagram.However, off-hook status of telephone set B cannot be detected by the fax side.• PP ControlWhen a normal ring arrives at the fax from the line, the CML 7 turns on resulting in theformation of an AC loop via circuit 13. The AC loop makes it possible for the modem to detectthe AC signals. If a user hooks up telephone set B after the first ring and enters the MF 2-digitspecial code in order to make the fax in the receive mode, then it becomes possible to detectthe MF signals along the remote.
