Installation
A. Ground Connections
The earth grounding lug or yellow/black pair on the modular RJ14 jack of the LM-24M
scanner must be connected to the positive of the talk battery for proper reference.
Normally this is the earth ground on most C.O. lines or analog PABX/KSU stations. To
test, use a voltmeter with the positive probe connected to the earth ground and the
negative probe to the ring side of a phone line. Measurements should be about 50 volts
on-hook and 30 volts off-hook.
C. Display Connections
Communication from the LM-24S scanner is accomplished over a single pair to the LM-24D display. The LM-24D
display receives data through pins 3 (red) and 4 (green) of a modular 6-wire jack or pins 2 (red) and 3 (green) of a
modular 4-wire jack.
Note: The LM-24D is sensitive to the polarity of this communication pair. The LM-24D will not be damaged by
reversed polarity on this pair but it will not function properly!
B. Phone Line Connections
All connections to the RJ-21X are in parallel with the C.O. lines or analog PABX/KSU stations. Use the table (above
right) to make the connections to the RJ-21X connector on the LM-24M scanner.
Note: The LM-24M scanner is factory set to 48 volts for C.O. lines or analog PABX/KSU stations. The LM-24M is
not sensitive to the polarity of the C.O. lines connected to the RJ-21X.
1T
1R
2T
2R
3T
3R
4T
4R
5T
5R
6T
6R
7T
7R
8T
8R
9T
9R
10T
10R
11T
11R
12T
12R
26
1
27
2
28
3
29
4
30
5
31
6
32
7
33
8
34
9
35
10
36
11
37
12
W/BL
BL/W
W/O
O/W
W/G
G/W
W/BN
BN/W
W/S
S/W
R/BL
BL/R
R/O
O/R
R/G
G/R
R/BN
BN/R
R/S
S/R
BK/BL
BL/BK
BK/O
O/BK
Line
Pins
Color
Receptionist’s Phone
25T
25R
50
25
V/S
S/V
BK/G
G/BK
BK/BN
BN/BK
BK/S
S/BK
Y/BL
BL/Y
Y/O
O/Y
Y/GN
GN/Y
Y/BN
BN/Y
Y/S
S/Y
V/BL
BL/V
V/O
O/V
V/GN
GN/V
V/BN
BN/V
38
13
39
14
40
15
41
16
42
17
43
18
44
19
45
20
46
21
47
22
48
23
49
24
13T
13R
14T
14R
15T
15R
16T
16R
17T
17R
18T
18R
19T
19R
20T
20R
21T
21R
22T
22R
23T
23R
24T
24R
VIKING
©
Don S.
Karen W.
Stacy R.
Dennis M.
Tom S.
Marie W.
Rachel O.
Bill H.
Al A.
Paul M.
Carol L.
Paul S.
Joanne M.
Rudy T.
Linda V.
Gail M
.
Shelly B.
Nichole S.
Al H.
Ken M
.
Greg Y.
Mick W
.
Mike L.
Tim
R.
Red
Green
Yellow Black
Optional
Earth Ground
Connection
To extension
telephones
Loop or
ground start
C.O. lines or
analog
PABX/KSU
station ports
LM-24D
Display
LM-24M Scanner
VIKING
©
MODEL LM-24M
VIKING ELECTRONICS, INC. HUDSON, WI 54016
LINE STATUS MONITOR
SCANNER
RJ21X
POWER DATA
RESET
1 2 3 4
COM
EARTH
GND
Earth
Ground
Lug
D. Multiple Displays
The LM-24M can power up to (3) displays. If you need to power more than (3) displays or for long runs between the
scanner and display, an optional PS-2 power supply must be used with each LM-24D display. Adding PS-2 power
supplies will efficiently double maximum run distances.
Stations
Typical Punch-Down Block
(not included)
120V AC
SENS
ADJUST
