15
SWITCH
BBBBBBBB
B
DD
CC
DD
D
DD
D
CCCCCC
DEVICE
A
A
A
DEVICE CONTROL
A
A
A
A
A
A
DEVICE DEVICE DEVICEDEVICEDEVICEDEVICE
BBBB
DDDD
0
I
CCCC
A
A
A
A
TERMIN
A
LTERMIN
A
LSWITCHTERMIN
A
LTERMIN
A
LMODEM
2
6
14
2
6
10
14
18
22
26
30
10
32 31
1920
28
24
27
23
16 15
11
4
8
3
7
16
12
15
8
7
3
29
17
25
21
13
9
1
5
13
9
5
1
A
17
12
11
4
0
I
0
I
Fig. 3 General layout showing terminal port and device port numbers.