ComLed - Simple COM Port & Modem Test Utility

This is a simple Windows utility for checking a modem (particularly a GSM modem) connected to a PC COM port.

The key features of this utility - not available on Hyperterminal and similar applications - are:

• The port in use, and its speed, are clearly visible without having to navigate into menus or option dialogues;
• The port in use, and its speed, are easily changed without having to disconnect or navigate into menus or option dialogues;
• The states of the control lines are clearly visible - thus showing immedately whether the modem is connected & active.

Buttons are also provided for sending a selection of AT commands to dentify the modem, and check its operation.

And that's about all it does, really! For features like auto-dialling, file transfers, etc - use a "proper" terminal application!

Using the Utility

The utility is a single, standalone executable - it doesn't need any installation, and shouldn't require any special DLLs, etc.

To start the utility, simply run the executable. The following dialogue should appear - select the required COM port from the list:

Once the port is selected, the main window appears:



The black central area is a terminal window; anything typed here will be sent to the selected COM port, and anything received from the port will be displayed here. There is no provision for local echo of typed characters.

The other elements of the window are as follows:

	The current Port is shown in the Title bar (top-left of the window).
	These "lights" indicate the states of the modem signals; The signal states are displayed, but no flow control is used. (The "Err" light indicates that the PC has detected an error).
	Checkboxes control the RTS & DTR outputs from the PC. The signal states are set manually, but no flow control is used.
	Set the baud rate; The rate changes as soon as it is selected. Other parameters are fixed at: 8 data bits, 1 stop bit, No parity, No flow control.
	The appearance of this button toggles with the Port state: When the Port is open, the button will close it; When the Port is closed, the button will open it.
	Re-display the port selection dialogue, to select another Port.
	Use this button to allow a port number to be manually entered (rather than choosing from a list). It causes this dialogue to display:
	Clears the terminal display.
	Sends AT to the modem; Any modem should respond with OK.
	Sends ATI to the modem; Any modem should respond with some identification information.
	Sends AT+CSQ to the modem; A GSM modem should respond with the current Signal Strength reading.
	Sends AT+CREG? to the modem; A GSM modem should respond with current GSM Registration status.
	Sends AT+COPS? to the modem; A GSM modem should respond with the currently-selected network operator.
	Sends AT+COPS=? to the modem; A GSM modem should respond with the list of available networks.
	Sends AT+CNUM to the modem; A GSM modem should respond with the SIM's phone number, if available.
	Sends AT+CGSN to the modem; A GSM modem should respond with its serial number.
	Sends AT+CGMR to the modem; A GSM modem should respond with its revision information.

Compatibility

The Utility works on Windows-XP, and may also wok on other versions;

It should work with any device that appears as a "COM Port" on the PC - including USB-to-Serial adaptors.

Disclaimer

This utility is presented in the hope that it may be of some use and/or interest; it is provided "as-is" and entirely without any warranty of any sort whatsoever - any use of it is entirely at your own risk.

Trademarks, trade names, etc are acknowledged as the property of their respective owners, and no endorsement or sponsorship by them is implied.

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