3Com ACCESSBUILDER 7000, Руководство пользователя

Страница: 38 / 60

A - 2 A
P P E N D I X
A: M
O D E M
S
P E C I F I C A T I O N A N D
I
N T E R F A C E
P
I N
A
S S I G N M E N T S
D ata Input
Serial binary. Complies with CCITT V.28. A ccepts levels ±3 volts to ±2 5
volts. (+)= space (-)= mark. Single wire ground return. 3000 to 7000
ohms load.
Data Output
Serial binary. Complies with CCITT V.28 ±1 2 volts nominal. Output
impedance 300 ohms.
Synchronization
RTS/CTS delay dependent on modulation format.
Equalizer
Automatic adaptive equalizer.
Error correction
V.42 LAPM and MNP4.
Data compression
V.42bis and MNP5.
Autodial - Autoanswer
Method
Pulse dial. 10 pps rate. Make period 33 msec. Break period 67 ms ec (UK
version). Interdigit period 800msec. Tone dial. On time 85 msec. ID time
85 msec. Duty cycle 50%.
Line Interface
600 ohm impedance. Bell tinkle suppression provided. Old and new
dial tone detection. Secondary dial tone detection for PABX use.
Progress tones and answer tone detection.