How to send command to serial port

Improve this answer. X Tian X Tian 9, 2 2 gold badges 31 31 silver badges 47 47 bronze badges. I'm not getting any output at all. Have any ideas? Possibly hardware flow control, either switch off with atty command or strap high in serial cable, search for null modem cable. X Tian 9, 2 2 gold badges 31 31 silver badges 47 47 bronze badges. You have answered this 10 mins after I wrote my answer above and you haven't added any further information at all! Oh sorry, I did not read your answer completly.

I saw that my answer is included in yours, so I will accept your answer as the correct one, as you described just what I have described. I don't know much about COM ports. Could you please explain what does "the serial device on the other end is not blocking" mean? Some issue with the firewall? Zibri Zibri 4 4 silver badges 9 9 bronze badges. This works great and provided a wonderful solution to my UART dilemma of downloading a file over the UART and providing feedback path to see if it got there successfully.

Thank you for posting! Let's get connected! To begin, navigate to the "Port" tab. On the "Port" dropdown here, select the number of your COM port. Then, make sure the baud rate and other settings are correct. You can select the baud rate from the dropdown, or type it in manually. With all of those settings adjusted, you'll have to click "Open" twice to close and re-open the port clicking "Change" doesn't work until after you've established a connection on a COM port.

That's all there is to that! Type stuff in the black ether above to send data, and anything received by the terminal will pop up there too. The ability to send long sequences of binary, hexadecimal, or decimal values is what really sets RealTerm apart from the other terminal programs we've discussed.

To access this function, head over to the "Send" tab. Then click into either of the two text boxes next to "Send Numbers". This is where you enter your number sequence, each value separated by a space. Once you have your string typed out, hit "Send Numbers" and away they go! Why would you need this you ask? This is a pretty cool setup -- you can control a 7-segment display by just typing in your terminal.

But what if you wanted to dim the display? You'd need to send two sequential bytes of value and 0. How would you do that with the handful of keys on a keyboard? Just as you can use RealTerm to send literal binary values, you can also use it to display them. On the "Display" tab, under the "Display As" section are a wide array of terminal display choices. You can have data coming in displayed as standard ASCII characters, or you can have them show up as hex values, or any number of other display types.

Incoming bytes are displayed as hexadecimal values. Can you decode the secret message?! RealTerm is preferred for more advanced terminal usage.

We'll use it when we need to send specific bytes, but for more basic terminal applications, TeraTerm is our go-to emulator. YAT is a user-friendly and feature-rich serial terminal.

It features text as well as binary communication, predefined commands, a multiple-document user interface and lots of extras. YAT is available to download at SourceForge. YAT features a multiple-document user interface MDI that consists of a single workspace with one or more terminals.

Each terminal can be configured according to the device it shall be communicating with. These extra features make a terminal especially easy to use:. Each terminal has its own monitor to display outgoing and incoming data.

The view can be configured as desired:. Most of these features can be enabled and configured, or hidden for a cleaner and simpler user interface. YAT is fully hosted on SourceForge. Feature Requests and Bug Reports can be entered into the according tracker. Both trackers can be filtered and sorted, either using the predefined searches or the list view.

Support is provided by a few simple helps integrated into the application, some screenshots on the SourceForge page, and the project's email if none of the above can help. YAT is implemented in C. NET using Windows. The source code is implemented in a very modular way.

NET based application that needs serial communication, command line handling or just a couple of convenient utilities. Testing is done using an NUnit based test suite. Project documentation is done in OpenOffice. CoolTerm is useful no matter which operating system you're using. However, it is especially useful in Mac OS where there aren't as many terminal options as there are in Windows. You can download the latest version of CoolTerm here.

To change the settings, click the Options icon with the little gear and wrench. You'll be presented with this menu:. Line mode doesn't send data until enter has been pressed. Raw mode sends characters directly to the screen. Once all your setting are correct, the Connect and Disconnect buttons will open and close the connection. The settings and status of your connection will be displayed in the bottom left corner. If you need to clear the data in the terminal screen, click the Clear Data icon with the large red X on it.

If you're getting annoyed with not being able to use the backspace, turn on 'Handle Backspace Character' under the Terminal tab under Options.

One awesome feature of CoolTerm is Hex View. Click the View Hex icon. The terminal's appearance will change slightly. The first column is just keeping track of line numbers. Notice the 0D and 0A that appear for carriage return and line feed. You can also use the Send String option to send entire strings of text. In the connection menu, select Send String. ZTerm is another terminal option for Mac users.

Compared to CoolTerm, it seems a lot less user friendly, however, once you find your way around, it's just as useful. This can be annoying if you have multiple connections available. This will bypass the auto connect and ask you to which port you'd like to connect. Here you can change the baud rate data rate ; parity, data, and stop bits; flow control; and turn local echo on or off. ZTerm has lots of other uses for network communication, but that is beyond the scope of this tutorial.

Have a command that you're typing constantly? Make a macro for it! As mentioned earlier, you can use command line interfaces to create serial connections.

The major limiting factor is the lack of connection options. Most of the programs we've discussed so far have a slew of options that you can tweak for your specific connection, whereas the command line method is more of a quick and dirty way of connecting to your device in a pinch.

Here's how to accomplish this on the three major operating systems. Open Terminal. See the Connecting to Your Device section for directions.

The screen will then ask if you are sure you want to disconnect. There are other options you can control from screen, however it is recommended that you only use this method if you are comfortable with the command line. Type man screen for a full list of options and commands. The screen command can also be used in Linux. There are only a few variations from the Mac instructions.

The fastest way to get to the command line in Windows is to click on the start menu, type cmd into the search field, and press Enter. To be able to issue Serial commands, you must first enter PowerShell. Type powershell to get into PowerShell command mode.

There may come a time when you need a device to be on a specific COM port. An example of this is, in older versions of TeraTerm, you could only connect to COM ports 16 and below. Thus, if your device was on COM 17, you'd have to change it to connect to it.

This problem has been addressed in newer versions of TeraTerm, but there are many other programs out there that only allow a certain number of COM ports. Here, you'll see a drop down menu with all the available COM ports in it. Some of them will have in use next to them. These are the ports that have been assigned to a serial device. Notice that COM 9 doesn't have an in use next to it because that is the port we are currently working with.

The in use next to COM 3 should go away. Step Open up Powershell 2. Enter [System. SerialPort]::getportnames 3. Step You need to know the baud rate to talk to your device.

Look it up in your manual. I want to talk to a programmable LCD that supports baud rate The other settings should also be adjusted accordingly. Pull down the scrollbar and select COM1.

Steps to write and execute a script Open the terminal. Go to the directory where you want to create your script. Create a file with. Write the script in the file using an editor.

Run the script using. How do you send serial commands using PuTTY? Category: technology and computing operating systems. The settings you need are "Local echo" and "Line editing" under the "Terminal" category on the left. To get the characters to display on the screen as you enter them, set "Local echo" to "Force on". To get the terminal to not send the command until you press Enter, set "Local line editing" to "Force on".

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