SCHIELE DL42N-22模块，DL42N-22说明书在线阅读

EIA-232-D标准是使用最广泛的标准终端/计算机和终端/调制解调器接口未完全理解。这可能是因为并非所有线路都是定义明确，许多用户认为没有必要遵循其应用标准。通常设计师只考虑他们的拥有设备，但最先进的是计算机对计算机或计算机到调制解调器的操作。系统应易于连接到任何其他系统。

SCHIELE DL42N-22模块EIA-232-D标准最初由贝尔公司开发通过调制解调器连接终端的系统。多次握手为此目的包括了线路。虽然握手是在许多应用中没有必要，线路本身仍然是一部分因为它们便于故障排除。表A-1列出了标准EIA-232-D互连。到正确解释这些信息，记住EIA-232-D是用于将终端连接到调制解调器。当计算机在没有调制解调器的情况下相互连接，其中一个必须配置为终端（数据终端设备：DTE）和其他作为调制解调器（数据电路终端设备：DCE）。自从计算机通常配置为与终端一起工作在大多数情况下被配置为调制解调器。对于高电平，信号电平必须介于+3和+15伏之间，并且低电平在-3到-15伏之间。并联连接装置可能产生超出范围的电压，与EIA-232-D相反规范。笔记：1.EIA-232-D高信号电平为+3至+15伏。低电平为-3至-15伏。并联连接装置可能会产生超出范围的故障与规范相反。

2.EIA-232-D接口旨在将终端连接到调制解调器当计算机在没有调制解调器的情况下连接时，一个必须配置为调制解调器，另一个配置为终端。实施水平有几个级别的一致性可能适用于典型EIA-232-D互连。最低限度要求是两条数据线和一个接地。完整的EIA-232-D的实施需要12条线路；

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;