Pre-Delivery Planning; 3274 Model La, 1B, Or Id To Local Channel Cables; 3274 Models 1C And Sic Communication Cable; 3274 Models 1C And Sic System Grounding - IBM 3274 Planning, Setup, And Customizing Manual

Pre-Delivery Planning
The 3274 Models lA, IB, and ID are installed by an IBM service representative. The
3274 Models IC and SIC, on the other hand, are set up by your personnel. To prevent
delays and help ensure a smoother 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 the
IBM service representative
3. Coordinate the activities of your personnel and/or the IBM service representative
3274 Model lA, IB, or ID to Local Channel Cables
The I/O interface and power sequencing cables between a 3274 Model lA, IB, or
ID
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.
3274 Models IC and SIC Communication Cable
The communication cable that connects the 3274 Modell C or 51 C to the modem or
channel service unit is delivered with the Models 1 C and 51 C. The standard cable length is
6.1 meters (20 feet); optional cable lengths of 3.0 meters (10 feet), 9.1 meters (30 feet),
and 12.2 meters ( 40 feet) may be specified. This cable is connected to the Models 1 C and
SIC by the setup personnel. Instructions for connecting the communication cable to the
3274 Models
1 C
and 51 C are provided by the 3274 Setup Instructions delivered with these
models. Connection to the modem or channel service unit should be discussed with your
supplier.
3274 Models 1C and SIC System Grounding
3274 Device Cables
1-6
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 Models IC and SIC 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 3274 Models IC
and SIC at the plant of manufacture.
Note: If you are replacing a 3271 or 3275 with a 3274 Model 1C or 51C, the modem
should already have signal ground and frame ground connected together. However, this
should be verified with your communications supplier.
Fan-Out Feature: This feature permits two or more control units to be connected to a
single modem. If the model has this capability, it is imperative that the signal ground and
frame ground wires be connected together in the modem.
The device cables are the coaxial cables that connect the 3274 to its attached display
. stations. and printers. These cables should be procured and installed before the delivery of
the 3274 and the units that will be attached to the 3274. Your personnel (or contractor)
will
connect these cables to the 3274 and the attached units.