Technical information

Integrators’ Reference Manual for ViewStation EX, ViewStation FX, and VS4000
40 www.polycom.com
15 RTS = 0
b
DTR = 0
a
CRQ = 0
All signals go low if Far
End or User hang up
is detected
DSR = 1 to 0, OR DCD
= 1 to 0
A falling edge on DSR
or DCD are interpreted
by the ViewStation FX
or VS4000 as a
hang-up
16 IDLE
DTR = 0
a
RTS = 0
b
CRQ = 0
IDLE
RI = 0
DLO = 0
ACR = 0
DSR = 0
a. DTR does not act as shown but remains high if DTR is set to ON
in the V.35 Advanced Setup screen.
b. RTS does not act as shown but acts as a resync pulse if
Security/Crypto-Resync is set to ON.
c. DSR is used as a ring-in indicate if DSR is set to ANSWER in the
V.35 Advanced Setup screen.
Table 2-23. Inbound Call State Machine
State
ViewStation FX or
VS4000 Signals Network Signals
1 Initial State:
DTR = 0
a
RTS = 0
b
CRQ = 0
Initial State:
RI = 0
DLO = 0
ACR = 0
DSR = 0
REMOTE USER
INITIATES CALL
2 RI= 0 to 1, or DCD= 0
to 1, or DSR= 0 to 1
c
3 Notify user of ring-in
d
4 System accepts call
Table 2-22. Dial-Out State Machine (Continued)
State
ViewStation or
VS4000 Signals
Network Signals