RS-232 回显本地与远程
是否有一个术语用于表示串行端口是否回显远程接收的字符与本地计算机回显本地发送的字符？我正在寻找建立一个 SCPI 命令来打开/关闭此远程回显协议。大多数串行接口系统是否在需要时仅依赖于本地回显字符？
Is there a term used for whether a serial port echos characters received remotely versus having the local machine echo characters sent locally? I am looking to establish a SCPI command for turning on/off this remote echo protocol. Do most serial interface systems rely solely on echo characters locally when desired?
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USConverters USB 转 RS485 紧凑型专业 (SN-060519) 转换器使用始终开启的回声信号。 RS485 是半双工通信，因此 USConverters 显然认为需要使用接收器/发送器来始终回显主机发送的内容，以表明字符/数据已到达转换器。
USConverters USB to RS485 Compact-Professional (SN-060519)converter uses a always on echo signal. RS485 is a half duplex communication so USConverters evidently felt the need to use the Receiver/Transmitter to always echo back what the host sent out to show that the character/data got the converter.
我见过这个 SCPI 命令：
I've seen this SCPI command:
否
当具有相对甚至绝对愚蠢（我们现在所说的）客户端的交互系统很常见时，几乎所有系统都使用到现在所谓的服务器的往返来进行字符回显。如果没有它，就不可能对用户体验进行任何控制。即使是纯机电电传打字机在 Unix 系统上也使用全双工。
少数具有本地回显功能的系统或多或少地模拟打孔卡输入，通常用于运行单个大型程序，与终端硬件配合运行客户信息系统或其他在线应用程序，而不是真正的交互式计算机访问。其中一些系统昂贵且复杂，并且运行着许多银行终端，但它们的交互设计几乎普遍不受尊重。
作为一个具体的例子，即使是所有交互式 Unix 远程客户端中的 0.1% 也不太可能使用过本地 echo。 （我确信这种情况在一些可怜的、现在被遗忘的大型机上发生过几次。）
话虽如此，我对你的应用程序并不熟悉，也许它足够简单，本地回显是有意义的。由于今天的客户端比昨天的“服务器”功能强大得多，因此当我们
ssh进入 CLI 进行一些本地系统管理时，我们几乎只能看到旧的范例。但即使在这种情况下，当今世界我们始终拥有“全双工”（远程回声）系统。
No
When interactive systems with relatively or even absolutely dumb (what we now call) clients were common almost all of them used a round-trip to what is now called the server for character echo. It simply wasn't possible to have any control over the user experience without it. Even the purely electromechanical teletypes used full duplex on Unix systems.
The few systems with local echo were more-or-less emulating punch card input and generally were used to run a single large program that cooperated with the terminal hardware to run customer information systems or other online applications, but not true interactive computer access. Some of these systems were expensive and sophisticated, and they ran a lot of bank terminals, but they were almost universally disrespected for their interactive design.
As a concrete example, it is unlikely that even 0.1% of all the interactive Unix remote clients ever used local echo. (I'm sure it happened a few times on some pathetic and now forgotten mainframe.)
Having said all that, I'm not familiar with your application and perhaps it is simple enough that local echo makes sense. Since today's clients are far more powerful than yesterday's "servers", we pretty much only see the old paradigm when we
sshinto a CLI to do some local system admin.But even in that case in today's world we always have a "full duplex" (remote echo) system.
我知道有两种不同的术语在使用......具体取决于您谈论的是终端设备还是主机。
过去......使用计算机通常意味着 VT-100 终端或类似的 RS-232 设备，通过调制解调器或硬线连接到主机。此类终端通常会
有一个 DIP 开关在“半双工”模式之间进行选择（在本地回显字符，
对于不支持同时传入和传出 I/O 的设备）和“全双工”
模式，远程设备负责回显它收到的任何输入。
Unix“stty”命令可以启用或禁用连接主机端的本地回显。这对于与仅针对半双工或全双工进行硬连线的传统设备进行互操作可能是必要的。
您可能会遇到描述此类配置的任一术语（半双工/全双工、主机回显开/关）。
在现代人机界面设备的背景下，全双工/“主机回显启用”是迄今为止最常见的配置。
另一方面，嵌入式设备很可能采用自定义协议，这些协议不涉及一侧通过连接回显其输入。
There are two different terminologies in play, that I'm aware of...depending on whether you're talking about a terminal device, or a host computer.
Back in the day....using a computer usually meant a VT-100 terminal or similar RS-232 device, connected via modem or hardline to the host. Such terminals would often
have a DIP switch selecting between "half duplex" mode (which echoed characters locally,
for devices that didn't support simultaneous incoming and outgoing I/O), and "full duplex"
mode, where the remote device was responsible for echoing any input it received.
The Unix "stty" command can enable or disable local echoing from the host side of the connection. This was probably necessary to interoperate with legacy devices that were hardwired for half-duplex or full-duplex only.
You are somewhat likely to encounter either terminology (half/full duplex, host echo on/off) to describe this sort of configuration.
In the context of modern human interface devices, full-duplex/"host echo enabled" is by far the most common configuration.
Embedded devices, on the other hand, are quite likely to employ custom protocols that don't involve one side echoing its input back across the connection.
据我记得，这个概念被称为“本地回声”，并且它再也没有被使用过。
As far as I recall, the concept is called "local echo", and it it's never used anymore.