SCHIELE DL42N-22模塊，DL42N-22說明書在線閱讀
EIA-232-D標準是使用最廣泛的標準終端/計算機和終端/調(diào)制解調(diào)器接口未完全理解。這可能是因為并非所有線路都是定義明確，許多用戶認為沒有必要遵循其應用標準。通常設計師只考慮他們的擁有設備，但最先進的是計算機對計算機或計算機到調(diào)制解調(diào)器的操作。系統(tǒng)應易于連接到任何其他系統(tǒng)。
SCHIELE DL42N-22模塊EIA-232-D標準最初由貝爾公司開發(fā)通過調(diào)制解調(diào)器連接終端的系統(tǒng)。多次握手為此目的包括了線路。雖然握手是在許多應用中沒有必要，線路本身仍然是一部分因為它們便于故障排除。表A-1列出了標準EIA-232-D互連。到正確解釋這些信息，記住EIA-232-D是用于將終端連接到調(diào)制解調(diào)器。當計算機在沒有調(diào)制解調(diào)器的情況下相互連接，其中一個必須配置為終端（數(shù)據(jù)終端設備：DTE）和其他作為調(diào)制解調(diào)器（數(shù)據(jù)電路終端設備：DCE）。自從計算機通常配置為與終端一起工作在大多數(shù)情況下被配置為調(diào)制解調(diào)器。對于高電平，信號電平必須介于+3和+15伏之間，并且低電平在-3到-15伏之間。并聯(lián)連接裝置可能產(chǎn)生超出范圍的電壓，與EIA-232-D相反規(guī)范。筆記：1.EIA-232-D高信號電平為+3至+15伏。低電平為-3至-15伏。并聯(lián)連接裝置可能會產(chǎn)生超出范圍的故障與規(guī)范相反。
2.EIA-232-D接口旨在將終端連接到調(diào)制解調(diào)器當計算機在沒有調(diào)制解調(diào)器的情況下連接時，一個必須配置為調(diào)制解調(diào)器，另一個配置為終端。實施水平有幾個級別的一致性可能適用于典型EIA-232-D互連。最低限度要求是兩條數(shù)據(jù)線和一個接地。完整的EIA-232-D的實施需要12條線路；
Introduction
The EIA-232-D standard is the most widely used
terminal/computer and terminal/modem interface, and yet it is
not fully understood. This may be because not all the lines are
clearly defined, and many users do not see the need to follow the
standard in their applications. Often designers think only of their
own equipment, but the state of the art is computer-to-computer or
computer-to-modem operation. A system should easily connect to
any other system.
The EIA-232-D standard was originally developed by the Bell
System to connect terminals via modems. Several handshaking
lines were included for that purpose. Although handshaking is
unnecessary in many applications, the lines themselves remain part
of many designs because they facilitate troubleshooting.
Table A-1 lists the standard EIA-232-D interconnections. To
interpret this information correctly, remember that EIA-232-D was
intended to connect a terminal to a modem. When computers are
connected to each other without modems, one of them must be
configured as a terminal (data terminal equipment: DTE) and the
other as a modem (data circuit-terminating equipment: DCE). Since
computers are normally configured to work with terminals, they
are said to be configured as a modem in most cases.
Signal levels must lie between +3 and +15 volts for a high level, and
between -3 and -15 volts for a low level. Connecting units in parallel
may produce out-of-range voltages and is contrary to EIA-232-D
specifications.Notes:
1. A high EIA-232-D signal level is +3 to +15 volts. A low level is -3
to -15 volts. Connecting units in parallel may produce out-of-range
voltages and is contrary to specifications.
2. The EIA-232-D interface is intended to connect a terminal to a
modem. When computers are connected without modems, one
must be configured as a modem and the other as a terminal.
Levels of Implementation
There are several levels of conformance that may be appropriate for
typical EIA-232-D interconnections. The bare minimum
requirement is the two data lines and a ground. The full
implementation of EIA-232-D requires 12 lines;
