
17
4 ![]()
 3 ![]()
 2 ![]()
 1
8 ![]()
 7 ![]()
 6 ![]()
 5
12 
 11 
 10 
 9
16 
 15 
 14 
 13
4 ![]()
 3 ![]()
 2 ![]()
 1
8 ![]()
 7 ![]()
 6 ![]()
 5
12 ![]()
 11 ![]()
 10 ![]()
 9
16 ![]()
 15 ![]()
 14 ![]()
 13
20 
 19 
 18 
 17
24 
 23 
 22 
 21
28 
 27 
 26 
 25
32 
 31 
 30 
 29
A
  | I 0  | 
  | 
  | I 0  | 
  | 
  | 
  | 
  | MODEM  | 
D  | C  | B  | A  | TERMINAL  | 
D  | C  | B  | A  | TERMINAL  | 
D  | C  | B  | A  | TERMINAL  | 
D  | C  | B  | A  | TERMINAL  | 
  | 
  | 
  | 
  | SWITCH  | 
  | 
  | 
  | 
  | SWITCH  | 
D  | C  | B  | A  | DEVICE  | 
D  | C  | B  | A  | DEVICE  | 
D  | C  | B  | A  | DEVICE  | 
D  | C  | B  | A  | DEVICE  | 
D  | C  | B  | A  | DEVICE  | 
D  | C  | B  | A  | DEVICE  | 
D  | C  | B  | A  | DEVICE  | 
D  | C  | B  | A  | DEVICE  | 
B  | 
  | 
  | A  | CONTROL  | 
Fig. 3 General layout showing terminal port and device port numbers.
15