Troubleshooting Serial (COM) Port Problems

If the foot pedal of the WavPlayer does not respond, this may indicate a serial (COM) port problem. While most computers have a free serial (COM) port, the port is not always truly available. In some cases a board mounted inside the computer (or PCMCIA card for laptops) may be using the port associated with the serial (COM) port. In addition to this, each serial communications device needs an interrupt request number (IRQ) and these numbers are limited in a PC. The end result is that although things look okay, you may still be having trouble with your communication port.

On most desktop PCs, you will find two serial (COM) ports. Older systems often have one 9-pin serial port and one 25-pin serial ports (these are D-shaped connectors on the back of the PC). They are typically configured as COM1 and COM2. On laptop computers, you will usually find only one serial (COM) port configured as COM1. Often when connecting an internal modem or other communication device, the serial ports will be reconfigured to a different COM port (such as COM3 or COM4)

If the WavPlayer functions properly when using a mouse but does not respond when using the foot pedal, follow the steps below to troubleshoot the problem.

1.  Check to see which serial (COM) ports are recognized by Windows

Right-click on the "My Computer" icon on your desktop. Select Properties from the drop down menu that appears. This will display the Properties window. Select the Device Manager tab at the top of the Properties window. From the Device Manager list, click the ‘+’ next to Ports. The Device Manager should look similar to the one below.

Note which COM ports are recognized by Windows. The WavPlayer foot pedal will need to use one of the recognized COM ports. The next thing to check is to see what COM ports are being used by your modem.

2. Modem COM port Usage

In the Device Manager shown above, click the ‘+’ next to Modem to view which modems are recognized by Windows. The Device Manager will display modems similar to below.

Double-click on the available modem or modems. Doing this will display the Modem Properties window. Select the Modem tab from the Properties window. You will see a screen similar to the one below.

The Modem Properties window displays the COM port being used by the modem. The COM port used by the WavPlayer foot pedal can NOT be the COM port being used by the modem.

Next check to see if your mouse is using a COM port.

3. See if you have a serial port mouse or a PS/2 mouse.

A serial port mouse may be using the resources of two COM ports. In the Device Manager, click the ‘+’ next to Mouse. Your device manager will look similar the one below.

Your mouse connects to your computer either via a serial (COM) port or a special PS/2 connector. A PS/2 mouse plugs into a small circular connector on the computer. A serial mouse plugs into one of the serial ports (D-shaped connectors with 9 pins). A PS/2 mouse does not use communications port resources on your computer, so you should have no problems. If you have a PS/2 mouse, you may skip to step 4.

A serial port mouse is often connected to COM1. Because the mouse is active at all times, COM1 cannot be used with the WavPlayer foot pedal. In addition, COM1 shares computer resources with COM3, so it is very likely that you will also not be able to use COM3 for your WavPlayer foot pedal. This still leaves you with COM2 or COM4, as long as a fax modem or other communications device does not use them.

You may consider converting to a PS/2 mouse if possible to free up a serial port. Check with a computer technician to see if you can change to a PS/2 mouse. If you do this, you can use the port that was being used by your mouse.

4. Check your Interrupt Request Settings (IRQs)

In the Device Manager, the word Computer appears at the top of the list as shown highlighted below.

Double-click on the Computer setting and the following Computer Properties window will appear.

On the left side of the Computer Properties windows, the IRQ numbers are shown. Check to see what device is shown by IRQ settings 03 and 04. In the example above, COM1 is using IRQ 04.

NOTE: The serial (COM) port used by the WavPlayer foot pedal cannot share an IRQ setting with another device. This means that if you see two devices by IRQ 04, for example, there is a port conflict and the WavPlayer foot pedal cannot use this port.

It doesn’t matter which IRQ setting the serial (COM) port is using as long as it is not being shared with another device.

5. Configure the WavPlayer COM port setting.

Open the WavPlayer software by clicking Start | Programs | Bytescribe | WavPlayer. Click the Ports menu as shown below.

You must select a COM port that is recognized by Windows (step 1) and is NOT used by your modem (step 2) and is NOT used by your mouse (step 3) and does NOT have a conflict with another device (step 4). Once you have set the COM port setting, open a file in the WavPlayer and try using your foot pedal. If you still have problems, continue with the next steps.

6. Look for other programs that might be using a serial (COM) port.

Check to see if you have software installed that may be using your serial (COM) port even if it is not being used right now. Examples of programs that may use the serial ports are programs for Un-interruptible Power Supplies (UPS), Digital Camera connectors, Digital Voice Recorder connectors, External Modems and many other similar software programs. If you determine that there are such programs that use the serial ports, you may need to uninstall these programs if they are causing a conflict.

7. Other considerations.

  • Serial Ports were not recognized in step 1.

If windows did not recognize any serial (COM) ports in step 1, but you do have 9-pin or 25-pin serial ports on the back of your computer, the serial (COM) ports may be disabled in your systems BIOS settings. Because the number of devices that can be added to a computer is often limited, unused ports are sometimes disabled to free up resources for other devices. If Windows does not detect your serial (COM) ports, you may need to have a computer technician check to see if the ports are disabled in the BIOS settings.

  • Serial (COM) Ports are detected by Windows and there are no conflicts, but the foot pedal still does not work.

There may be a problem with the serial port itself. Usually a serial port is connected to the motherboard of a computer by a small cable. Have a computer technician check to see that the serial port cables are properly connected to the motherboard. Also possibly try replacing the cable to see if the cable is faulty or a non-standard cable.

  • 25-pin serial ports.

Many older computers have 2 or more serial ports. Often one port is a 9-pin port (usually COM1) and a second is a 25-pin port (usually COM2). If you have an available 25-pin serial (COM) port, you will need to purchase and 25-pin to 9-pin adapter (from Radio Shack or similar). The port should work fine with the adapter.

Last update: 10:03 AM Thursday, July 24, 2008

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