20
Mode Dip Switch Settings U301
S301 controls the operating mode for System B and S302 controls the operating mode for System A.
Settings are summarized as follows:
Full-Duplex Definition: Both sides of the line can talk simultaneously.
Half-Duplex Definition: Only one side of the line can talk at a time and the other side must wait until the first side is
done talking before responding. 4-wire systems have priority over 2-wire system in Half-
duplex mode.
Tone Test Mod e: Disables internal suppression of tones.
Full-Duplex Definition: Both sides of the line can talk simultaneously.
Half-Duplex Definition: Only one side of the line can talk at a time and the other side must wait until the first side is
done talking before responding. 4-wire systems have priority over 2-wire system in Half-
duplex mode.
Noise Suppression: The unit suppresses background noise in absence of speech. Configuration 3 disables this
suppression.
TABLE 3. Mode DIP Switch Settings for Programmed Chip P/N 90157640500 (version 1.0)
Switch Settings Description
1234
Open Open Open Open Configuration 1, Full-Duplex Mode (Default)
Closed Open Open Open Configuration 2, Half-Duplex Mode
Open Open Open Closed Configuration 3, Tone Test Mode
TABLE 4. Mode DIP Switch Settings for Programmed Chip P/N 90157640500 (version 1.1)
Switch Settings Description
1234
Open Open Open Open Configuration 1, Full-Duplex Mode (Default)
Closed Open Open Open Configuration 2, Half-Duplex Mode
Open Open Open Closed Configuration 3, Full-Duplex Mode, Noise Suppression Disabled