Configuring the Modem
SW2-1 − Fast Poll/FSK (high- & low-speed modes)
SW2-1 ON = Low-Speed Mode (FSK)
OFF = High-Speed Mode (Fast Poll)
SW2-1 configures the modem for either low-speed (FSK) mode or high-speed (Fast Poll) mode. As a result, the SW2-1 setting you choose determines the switch definitions for the other switches.
cFor high-speed mode, the configuration switches follow the definitions in Table 2-1.
cFor low-speed mode, the configuration switches follow the definitions in Table 2-3.
SW2-2 − CD Delay (low-speed mode only)
SW2-2 ON = 23 milliseconds
OFF = 6 milliseconds
SW2-2 controls the Carrier Detect (CD) delay and is valid for low- speed mode only. Setting this switch to ON configures the modem to turn on CD 23 milliseconds after it detects a valid carrier signal. Setting this switch to OFF configures the modem to turn on CD 6 milliseconds after it detects a valid carrier signal.
SW2-3 − Turnaround Squelch Delay (low-speed mode only)
SW2-3 ON = 0 milliseconds
OFF = 8 milliseconds
SW2-3 controls the turnaround squelch delay and is valid for low-speed mode only. Setting this switch to ON configures the modem to enable its receiver immediately after the Request To Send (RTS) signal is turned off. When this switch is set to OFF and the modem is configured for 2-wire mode (SW2-7 set to ON), the modem squelches the receiver for 8 milliseconds after RTS is turned off to prevent far-end echoes from causing data errors.