Using a USB to Serial Adapter and Terminal Emulator in Windows 7 to Communicate with a DM101

Using a USB to Serial adapter and Terminal Emulator in Windows 7 to communicate with a DM101

Z Technology Application Note No: 40

This application note outlines the simple process of installing and using a USB to Serial adapter, and a Terminal Emulator program on a Windows 7 PC to communicate with a Z Technology DM101 ATSC receiver.

Most Windows 7 PCs and Laptops no longer include an RS-232 COM port or the but have a multitude of USB ports. Windows 7 has dropped Hyperterminal, the Terminal Emulator that was in Windows 98 and Windows XP, a generic Terminal Emulator program can replace Hyperterminal. This Application note will introduce a generic open source Terminal Emulator named PuTTY.

Z Technology recommends using a USB 2.0 port on your PC or Laptop, a USB to Serial adapter containing a “Prolific” chip. These are inexpensively available as a Sewell model SW-1301. See http://www.sewelldirect.com

Step1: Install the USB to Serial Driver for the USB to Serial adapter. See the manufactures instructions. Typically this consists of inserting a CD ROM supplied with the USB to Serial adapter, then running an installation program. If you don’t see a choice to install a driver for Windows 7, choose the driver for Windows Vista.

Step 2: Insert the USB to Serial adapter into an available USB 2.0 port on your PC or Laptop. Some balloon messages should appear about finding drivers for the new device. Then more balloon messages about the driver installed, the device ready for use. Windows has created a virtual COM port on the PC. You will need to find out the COM port number, in order to use a terminal emulator program to communicate with the DM101.

Step 3: Find the port number for your Virtual COM port. Click the Windows Start button, the in the Search programs and files box type Device Manager and hit Enter. You should see a screen like the one below.

USB to Serial Adapter with Windows 7 Application Note

Double click on Ports(COM & LPT) and you should see a screen like the one below.

Note: When a USB to Serial adapter is plugged into a USB port a COM port number Windows reserves a COM port number for that device. If you plug the adapter into a different USB port Windows will assign a different COM port number. It’s a good idea to always plug your USB to Serial adapter into the same USB port to avoid COM port numbering confusion.

We see above that Windows has assigned COM4 to our USB to Serial adapter.

Step 4: Install a Terminal Emulator. In this example we will install a simple open source terminal emulator called PuTTY. Follow the links at http://www.putty.org to 2 USB to Serial Adapter with Windows 7 Application Note download putty.exe for windows. You can save the putty.exe executable to your desktop. Once complete you will see the putty.exe icon on your desktop.

Step 5: Configure PuTTY. Double click on the putty.exe icon, a configuration screen appears.

Step 6: The screen changes to the one below. Under Connection Type: click Serial Change the COM number to for situation, in this example COM4

3 USB to Serial Adapter with Windows 7 Application Note

Step 7: In the left Category column click Terminal, the screen below appears, Under Set various terminal options check Implicit LF in every CR, in the Line discipline options-Local Echo select Force on.

Step 8: In the left Category column click Serial, the screen below appears, under Flow Control select None.

4 USB to Serial Adapter with Windows 7 Application Note

Step 9: In the left Category column click Session, this brings you back to the first screen that now looks like the screen below. In the Saved Sessions box type in an appropriate name for this configuration, in this example DM101 on COM4, the click the SAVE button.

5 USB to Serial Adapter with Windows 7 Application Note

Now you have a saved configuration that you can load in the future.

Step 10: Click the OPEN button and PuTTY will start, with the configuration you just created. You will see the screen below.

Step 11: Test the communication. Make sure that you have the USB to Serial Adapter plugged into the female end of the RS-232 cable that came with the DM101, and the other side of the cable, the male end, plugged into the back of the DM101, and the DM101 is plugged into power, and the Front LED display show a channel number. Type a ? at the prompt, you should see the DM101 respond with the Help message.

6 USB to Serial Adapter with Windows 7 Application Note

You can now use the PuTTY terminal emulator to configure, control, and monitor the DM101 using the Z-Link protocol described in the DM101 User Manual.

If you don’t see the above response, you’ll need to go back and check the settings. To check the settings, right click on the putty.exe banner at the top of the window. That will take you back to the putty configuration screen.