Predelivery Planning - IBM 3270 Manual

Predelivery Planning
Local Channel Cables
Communication Cable
The local channel-attached models of the 327 4 are installed by an IBM \_,,
service representative. The remotely attached models, on the other hand,
are set up by your personnel. To prevent delays and help ensure a
~moother
installation/setup, it is recommended that a designated person in
your organization: ,
1. Compile the installation-dependent information described in this
section.
2. Distribute the installation-dependent information to the appropriate
personnel or to the IBM service representative.
3. Coordinate the activities of your personnel and/or the IBM service
representative.
The I/O interface and power sequencing cables between a 327 4 and a local
channel will be installed and connected by IBM. However, these cables
must be ordered by cable order unless you are replacing a 3272 with a 3274,
in which case, the same cables can be used.
The communication cable that connects the remotely attached 327 4 to the
modem or channel service unit is delivered with the 327 4. This cable is '\-..._./
connected to the 3274 by the setup personnel. Instructions for connecting
the communication cable to the 3274 are provided by the 3274 Setup
Instructions delivered with these tnodels. Connection to the modem or
channel service unit is described in Appendix F.
System Grounding for a Remotely Attached 8274
1-10
Frame ground (EIA RS232 or CCITT V.28 pin 1) and signal ground (EIA
RS232 or CCITT V.28 pin 7) should be connected together at one point only.
This can be either in the 3274 or in the modem or channel service unit. It
is recommended that, if possible, this connection be made in the modem or
channel service unit.
In Europe/Middle East/Africa countries, the majority of modems do not
have this connection made. For this reason, connection has been made
within the remotely attached 3274 models at the plant of manufacture.
Note: If you are replacing a 3271or3275 with a 3274 Model lC, 21C, 31C,
or 51C, the modem should already have sig:qalground and frame ground
connected together. However, this should be verified with your
communication supplier.
Fan-Out Feature: This feature permits two or more control units to be
connected to a single modem. If the modem has this capability, it is
imperative that the signal ground and frame ground wires be connected
together in the modem.
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