GDK-100
DIGITAL KEY TELEPHONE SYSTEM
117
3.5.6.6
Contact Assignments of RJ21 type Connectors on Analog CO Boards.
Table 3.5.6.6.a. shows the contact assignments of RJ21 type connector on LCOB.
Punch-Down LCOB
connector
LCOB
Line
Block Pin
Pair
Pin
Color-Code Designation
No
1
1
26
WH/BL
CO1-T
1
2
1
BL/WH
CO1-R
3 2
27
WH/OR
CO2-T
2
4
2
OR/WH
CO2-R
5 3
28
WH/GN
CO3-T
3
6
3
GN/WH
CO3-R
7 4
29
WH/BN
CO4-T
4
8
4
BN/WH
CO4-R
9 5
30
WH/SL
- -
10 5
SL/WH
11 6
31
RD/BL
12 6
BL/RD
13 7
32
RD/OR
14 7
OR/RD
15 8
33
RD/GN
16 8
GN/RD
17 9
34
RD/BN
18 9
BN/RD
19 10
35
RD/SL
20
10
SL/RD
21 11
36
BK/BL
22
11
BL/BK
23 12
37
BK/OR
24
12
OR/BK
25 13
38
BK/GN
26
13
GN/BK
27 14
39
BK/BN
28
14
BN/BK
29 15
40
BK/SL
30
15
SL/BK
31 16
41
YL/BL
32
16
BL/YL
33 17
42
YL/OR
34
17
OR/YL
35 18
43
YL/GN
36
18
GN/YL
37 19
44
YL/BN
38
19
BN/YL
39 20
45
YL/SL
40
20
SL/YL
BL:BLUE
41 21
46
VI/BL
BK:BLACK
42
21
BL/VI
BN:BROWN
43 22
47
VI/OR
OR:ORANGE
44
22
OR/VI
WH:WHITE
45 23
48
VI/GN
GN:GREEN
46
23
GN/VI
SL: SLIVER
47 24
49
VI/BN
VI:VIOLET
48
24
BN/VI
RD:RED
49 25
50
VI/SL
YL:YELLOW
50
25
SL/VI
Table 3.5.6.6.a
LCOB Wiring