Rs-232-C Junction Panel; Device Types Accepted; Variations From Rs-232-C - HP 27140A Hardware Reference Manual

RS-232-C Junction
Panel
Device Types Accepted
Variations from RS-232-C
3-2 Functional Description
Standard Cable
/
Component
Side
Multiplexer peA
\
ExtenSion Cable
<optionaD
Figure 3-1. UP 27140A Sub-assemblies
The RS-232-C Junction Panel has six 25-pin female data-communication
connectors. Each 25-pin connector on the panel is the port to a particular
communications channel. The data lines, on pins 2, 3, and 7, are
protected from overvoltage by transorbs inside the panel.
For information about attaching peripherals to the RS-232-C Junction
Pane~
see Chapter 2, "Installatiori/Configuration", the computer system
manuals and the manual for the peripheral you are attaching. If you in-
tend to make your own cables for a non-Hewlett-Packard peripheral, see
Chapter 6, and please read the next two paragraphs carefully.
Each port has the signal lines to support both Data Communication
Equipment (DCE), such as modems, and Data Terminal Equipment
(DTE), such as terminals. The data lines are arranged to accept data
directly from DTE. This feature makes the computer appear to
be
a data
communications device to the terminal. If you are going to attach DCE to
one of the ports, the connecting cable must redirect the data by crossing
the lines from pins 2 and 3 of the DCE to pins 3 and 2 at the port.
Two of the signals from a peripheral must go to non-standard locations in
ports on this panel. If the peripheral has a ring indicator signal (RI), it
must enter the port on pin 9. The clear to send signal (CS) from a
peripheral must enter the port on pin 22.