IBM 3708 Planning And Installation page 227

Section 2. Minimum Connections
Required for
IBM 3708 EIA 232C
Cable
The following minimum requirements for IBM 3708 EIA 232C cables are described
in this section:
• Minimum connections required for SNA host DCE cables
• Minimum connections required for SNA host DTE cables, modem eliminators,
or null modems
• Minimum connections required for asynchronous ASCII DCE cables
• Minimum connections required for ASCII DTE cables, modem eliminators, or
null modems.
Minimum Connections Required for SNA Host DCE Cables
The following chart shows the minimum electrical connections required.
The IBM 3708 has been extensively tested with the IBM cables described in the
preceding sections. Cables built without the same bulk cable or without the same
shielding connections may result in noise or operational problems.
Do not use 25-pin conductor cables.
SNA Host DCE Cable
Signal Name
Frame Ground
not used
Transmit Data **
Receive Data
RTS **
CTS
OSR
Signal Ground
DCD
not used
not used
not used
not used **
must not be connected
not used **
Transmit Clock
not used
Receive Clock
not used **
not used
DTR **
not used **
not used
not used **
DTE Transmit Clock
not used
3708
25 Pin Male
Connector
Pin
Remote
Connector
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
- - - outer shield - - -
------------2
-------------3
--------------4
- - - - - - - - - - - - 5
--------------6
- - - inner shields - - - - - 7
----------------8
1 5 - - - - - - - - - - 15
16
1 7 - - - - - - - - - - - 1 7
18
19
20 - - - - - - - - - - - 20
21
22
23
2 4 - - - - - - - - - - - 24
25
• Outer shield clamped to connector shell.
•• These pins must not be driven via the attaching equipment (modem. modem eliminator. or host).
See Chapter 9. section "3708 Problems Related to Cables or Equipment".
Pin 13 must not be connected.
Pin 24 is only required if the 3708 is providing transmit and receive clocKing.
D-6
3708 Planning and Installation