Xerox 3300MFP Service Manual - Page 64

Theory of Operation Line Interface The Line Interface provides the connection between the system and the external telephone line. Main functions are Line Interface, Telephone Connection and Line Condition Monitoring. Telephone Line Connection ■ a) Modular Plug: RJ-11C ■ b) LIU PBA Modular Type: 623 PCB4-4 ■ c) Line Code Length: 2500 ± 50 mm ■ d) Line Code Color: Black ON HOOK state Characteristic 1. DC Resistance a) DP Dial Mode (Direct Current 30 mA): 50 ~ 300 ohm b) DTMF Dial Mode (Direct Current 20 mA): 50 ~ 540 ohm 2. Ring Sensitivity a) Ring detection Voltage: 40 Vrms ~ 150 Vrms (condition: Current = 25 mA, Frequency = 15 Hz) product Margin: 30 Vrms ~ 150 Vrms b) Ring detection Frequency: 15.3 Hz ~ 68 Hz (condition: Voltage = 45 Vrms, Current = 25 mA) product Margin: 15 Hz ~ 70 Hz c) Ring detection Current: 20 mA ~ 100 mA (condition: Voltage = 40 Vrms, Frequency = 20 Hz) product Margin: over 15 mA 3. False Ring Sound a) Ring Frequency: 750 Hz + 1020 Hz b) Ring interrupt Cycle: On/Off depending on input Ring Signal Cycle. 2-22 Phaser 3300MFP Service Manual