SDP660 – USER MANUAL
TNM-U-E-0114
Jun 15 (Iss. 1.4)
Page 33
BASIC OPERATIONS
5.12.3
Receiving Duplex Calls on the SDP660
In a Full Off Air Call Set Up (FOACSU) system, the radio will start ringing and the telephone icon
will be displayed. Once
the call is answered, ‘PABX’ will be displayed on the screen along with
the duplex icon
indicating that simultaneous two-way communication is activated. Calls can be
answered by either pressing the PTT button or the green connect button. See
Figure 12
below.
Figure 12. SDP660 Receiving Duplex Call.
For Off Air Call Set Up (OACSU) systems, the radio will automatically answer any incoming duplex
calls.
5.12.4
Initiating Duplex Calls from the SDP660
To make a call from the radio, on the keypad, dial *8 followed by the extension number, then press
# or the PTT button. While the call is waiting to be answered by the recipient, the telephone icon
and ‘CALLING’ will be displayed. Once the recipient has answered the call, the duplex icon will be
displayed.
5.12.5
Disconnecting the call
Duplex calls can be terminated by either party hanging up (radio users press the red End
Call/Cancel
button), or the ‘Radio to Line Timer’ expires.
In noisy environments, it is recommended that ‘PTT TX Control for Duplex Calls’ checkbox is
enabled. This prevents the microphone from automatically transmitting continuously and will allow
users to PTT to enable the microphone for each transmission. See
Figure 13
below.
Figure 13. FPP
– PTT TX Control for Duplex Call.
If the PABX caller is experiencing any audible feedback or echo,
in the FPP under the ‘Global’ >
‘Audio’ section, reduce the ‘Earpiece Volume Offset’ and ‘Mic Gain’ settings. See
Figure 14
overleaf.