When you order CDP cables from the manufac-
turer, he will take care of the pin connections. But,
understanding how they work will be necessary
when the input adaptor cable is constructed (see
later section).
If your siring of CDP cables makes a cable with a
tolal of 24 takeouts, they will be arranged in the
field just like the earlier example with two 24-chan-
nel refraction cables. It is also possible to order
CDP cables to construct 48 or 60 (or more) takeout
cables, so that the rollalong switch could be posi-
tioned on either end of the line. Or, with multiple
sets of these cables, you can position at the center
of the line and have a full 96 or 120 inputs. Usually,
the limiting factor is the weight and length of cable,
and combinations are chosen to make the cables
easy to handle (normally a function of overall
length and number of conductors). One popular
combination for shallow surveys is 12 takeouts and
48 pairs of conductors, but many others are com-
mon.
4. Constructing Input Adaptor Cables
Because of the wide variety of connectors used on
geophone cables, the rollalong swilch does not in-
clude input adaptor cables. They arc avililablc as
a
special order. Consult factory for pricing and
availability.
The wiring diagram for the inpul connectors is rcla-
tively simple.
There are 4 (or 5) 50-pin input connectors, and one
(or two) identical output connectors. Each is
labeled on the case with the gcophonc or channel
number groups.
The connector pins are arranged with the
following
number sequence pattern:
The fust channel in each group of 24 chnnncls is
connected to pins 1 and 26. The last channel is con-
nected to pins 24 and 49. Pins 25 and 5O arc not
used (see Figure 7).
----Input Connectors ---
Outputs .
Pin Station Station Station Station Station
Channel Channel
Nos.
1-24
25-48
49-72
73-96
97-120
1-24
25-48
1/26
1
2 5
4 9
7 3
9 7
1
2 5
2/27
2
2 6
5 0
7 4
9 8
2
2 6
3/28
3
2 7
5 1
7 5
9 9
3
2 7
4/29
4
2 8
5 2
7 6
1 0 0
4
2 8
5/30
5
2 9
5 3
7 7
1 0 1
5
2 9
6/31
6
3 0
5 4
7 8
1 0 2
6
3 0
7/32
7
3 1
5 5
7 9
1 0 3
7
3 1
8/33
8
3 2
5 6
80
1 0 4
8
3 2
9/34
9
3 3
5 7
8 1
1 0 5
9
3 3
10135
1 0
3 4
58
8 2
1 0 6
1 0
3 4
11/36
1 1
3 5
59
8 3
1 0 7
1 1
3 5
12/37
1 2
3 6
6 0
84
1 0 8
1 2
3 6
13138
1 3
3 7
6 1
8 5
109
1 3
3 7
14/39
1 4
38
6 2
86
1 1 0
1 4
3 6
15/40
1 5
3 9
6 3
8 7
1 1 1
1 5
3 9
16/41
1 6
4 0
6 4
88
1 1 2
1 6
4 0
17/42
1 7
4 1
6 5
89
1 1 3
1 7
4 1
16/43
1 8
4 2
6 6
9 0
1 1 4
1 8
4 2
19/44
1 9
4 3
6 7
9 1
1 1 5
1 9
4 3
20/45
2 0
4 4
68
9 2
1 1 6
20
4 4
21/46
2 1
4 5
6 9
9 3
1 1 7
2 1
4 5
22/47
2 2
4 6
7 0
9 4
1 1 8
2 2
4 6
23/40
2 3
4 7
7 1
9 5
1 1 9
2 3
4 7
24/49
2 4
48
7 2
9 6
1 2 0
2 4
48
Figure 7, Input and output wiring table for Models RS-96/24
and RS-12O/48
switches.
The
Appendix
in-
cludcs diagrams for
some common adaptor
cables.
Geosluff
RS-96/24 & RS-120/48
Page 5
