Polycom ViewStation EX4000 - Manual (Page 53)

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