Polycom VS4000 User Manual

Page of 150
Chapter 2 - Technical Information
© Polycom, Inc.
43
Table 2-25.  Non-dialed Network-Initiated Call State Machine
 State
ViewStation FX or 
VS4000 Signals
Network Signals
1
Initial State:
DTR = 0
a
RTS = 0
b
CRQ = 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.
Initial State:
RI = 0
DLO = 0
ACR = 0
DSR = 0
USER INITIATES 
CALL
2
DCD = 0 to 1
3
DTR = 1
a
4
RTS = 1
b
5
DATA FLOW STARTS
DATA FLOW STARTS
User hang-up
Far end hang-up
6
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 is interpreted 
by the FX/ VS4000 as 
a hang-up
DCD= 0
c
c. If DCD filter is set to ON in the V.35 Advanced Setup screen, 
the system does not react to a low DCD until DCD has been low 
for 60 seconds.
7
IDLE
DTR = 0
a
RTS = 0
b
CRQ = 0
IDLE
RI = 0
DLO = 0
ACR = 0
DSR = 0