IBM System/34 Maintenance Manual page 483

Switches
R
H
P
G
N
F
M E
L 0
K
C
J B
I
A
A-A2H2 (line 1); A-A2H4 (line 2)
8
7
6
5
4
3
2
Set switches N, S, T, U, and V on and switch P off.
Set the transmit level switches A through Hand
R
as shown in the table at right.
The remaining switches are set for:
• 4-wire nonswitched line (set I on and M off)
• 2-wire nonswitched line (set I off and M on)
Also attach a jumper from A-A2H2G02 to
A-A2H2G09 and a jumper from A-A2H2J05
to A-A2H2J13 (line 1); attach a jumper from
A-A2H4G02 to A-A2H4G09 and a jumper
from A-A2H4J05 to A-A2H4J13 (line 2).
• Clear-to-send delay of:
-30 ms; set K on and J off
(recommended for a 4-wire
nonswitched line)
-80 ms; set K off and J on
!(use only for a special short
2-wire nonswitched line)
-230 ms; set K and J off
(recommended for a switched
line or a 2-wire nonswitched line)
Note:
The clear-to-send delay must always be longer
than the echo clamp delay.
Transmit Level
A. in the table below indicates that a
switch must be on to make a selection.
Set the switches to the needed transmit
level.
level in
Decibels
o
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
-18
Transmit level Switches
A B
C 0
E F G
H R
•
•
•
•
•
•
•
•
• •
• •
•
•
• •
• •
•
•
• •
• •
• •
• •
• •
•
•
• Echo clamp delay of:
- 0 ms; L can be set on or off because the
o
ms delay is automatically selected if
the 30 ms clear-to-send delay is selected.
50 ms; set Lon
(nonswitched or switched line)
150 ms; set L off
'(recommended for a switched
'line or a 2-wire nonswitched line)
Figure 31-22. Switch Settings for World Trade Nonswitched Network
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31-310 '
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