MVME197LE/D2A-1
A
EIA-232-D
INTERCONNECTIONS
The EIA-232-D Standard is the most widely used interface between terminals
and computers or modems, and yet it is not fully understood. This is because
all the lines are not clearly defined, and many users do not see the need to
conform for their applications. A system should easily connect to any other.
Many times designers think only of their own equipment, but the state-of-the-
art is computer-to-computer or computer-to-modem operation.
The DIA-232-D Standard was originally developed by the Bell System to
connect terminals via modems. Therefore, several handshaking lines were
included. In many applications these are not needed, but since they permit
diagnosis of problems, they are included in many applications.
Table A-1 lists the standard DIA-232-D interconnections. To interpret this
information correctly it is necessary to know that EIA-232-D is intended to
connect a terminal to a modem. When computers are connected to computers
without modems, one of them must be configured as a terminal and the other
as a modem. Because computers are normally configured to work with
terminals, they are said to be configured as a modem. Also, the signal levels
must be b3 and +15 volts for a high level, and between -3 and -15 volts
for a low level. Any attempt to connect units in parallel may result in out of
range voltages and is not allowed by the EIA-232-D specifications.
Summary of Contents for MVME197LE
Page 1: ...MVME197LE Single Board Computer User s Manual MVME197LE D2 ...
Page 12: ...xii ...
Page 14: ...xiv ...
Page 22: ...Hardware Preparation and Installation 2 2 User s Manual 2 ...
Page 30: ...Hardware Preparation and Installation 2 10 User s Manual 2 ...
Page 37: ...Memory Maps MVME197LE D2 3 7 3 ...
Page 40: ...Operating Instructions 3 10 User s Manual 3 ...
Page 42: ...Operating Instructions 3 12 User s Manual 3 ...
Page 44: ...Operating Instructions 3 14 User s Manual 3 ...
Page 46: ...Operating Instructions 3 16 User s Manual 3 ...
Page 48: ...Operating Instructions 3 18 User s Manual 3 ...
Page 60: ...Functional Description 4 2 User s Manual 4 ...