Chapter 2 - Technical Information
© Polycom, Inc. 39
State Machine

The V.35/RS-449/RS-530 state machine controls how the

V.35/RS-449/RS-530 interface signals handshake with the network

interface equipment while the call is being established. The

following tables describe the machine states.

Table 2-22. Dial-Out State Machine
State
ViewStation or
VS4000 Signals Network Signals
1Initial State:
DTR = 0a
RTS = 0b
CRQ = 0
USER INITIATES
CALL
Initial State:
RI = 0
DLO = 0
ACR = 0
DSR = 0
2DTR = 1a
3Wait 10 ms
4CRQ = 1
5PND = 1
6Set Digit
(NB1,NB2,NB3,NB4)
7DPR = 1
8PND = 0
9DPR = 0
10 If not last digit, go to
state 4; else continue
11 Call connects on
network
12 DSR = 1 AND/OR
DCD = 1
(AND/OR DSR = 1 c
13 RTS = 1b
14 DATA FLOW STARTS DATA FLOW STARTS
User Hang-up Far end hang-up