Westermo TD-29 - Manual (Page 11)

11 6611-2002
Functional description
Block diagram
Amplifier S1:6
S1:7
CTS RD TD SG RTS
RTS LED
CTS LED
TD LED
RD
LED
DCD
LED
DSR CTS RTS TD RD SG B A B’ A’
Screw terminal D-Sub
1 2 3 4 5 6 7 8 2 3 5
0V
0V
F1 0V
+5V
–5V
0V
S2:4
S2:3
S2:2
S2:1
5V
0V
5V
0V
5V
6 7 8 9
MCU
FSK
Demodulator
Isolated
Power Supply
S1:4
0V
0V
PWR
LED
Line
switch
Line
Power Supply
RS-422/485 connection
4-wire 2-wire
9
8
7
6
5
7
6
5
A’
B’
A
B
A
B
A’
B’
Receiver
Receiver A/A’
B/B’
B/B’
A/A’
Twisted pair
Twisted pair
TD-29 TD-29
Transmitter
Transmitter
RS-422
equipment
RS-485
equipment
Transmitter/
Receiver
Transmitter/
Receiver
NC NC