View source for Transmission Failed Message When Testing Communications

== Questions ==

'''Why do I get a Transmission Failed error in Activehome?'''

== Answer ==
A number of our software products communicate with hardware devices that are plugged into a serial port (if your device is USB, this article does not apply). Problems with communication or proper responses can be can be caused by several issues. Please see our suggestions below.

Many computers have at least one serial port, generally two. These are in the form of either a 9-pin male port, or a 25-pin male port. A serial port is often commonly referred to as a COM port. These can be configured to be COM1, COM2, COM3, or COM4.

If you are unsure which COM ports are in use on your computer, you can easily identify them from Windows Device Manager. 

Right-click on My Computer from your desktop--on windows 98, choose the Device Manager tab; or in windows ME, 2000, and XP, select the Hardware tab, and then press the Device Manager button.

Once you are in the Device Manager, will look in the alphabetical list for Ports (COM & LPT). Under this, you can identify your COM ports. If you notice that either of these has a red x, or yellow exclamation mark, you have a problem with this port's driver in your operating system. Please contact your computer manufacturer for support to resolve this.

If you notice you have more than one port listed, make sure that they are not COM1 & COM3, or COM2 & COM4. These combinations use the same resources in your computer, and even though Windows can handle them sharing, other installed software will interfere.
Internal modems are commonly installed in systems and setup to use COM3 or COM4, while the serial Ports COM1 or COM2 are still configured for your use. Depending on the modem type and driver you may be sharing resources and may experience problems. For support, please contact your computer manufacturer.

If you have checked all of these things, there may be another software blocking communications on the port where X10 hardware is connected. The most common offenders are the following:

*Palm is one of the most commonly used PDA terminals, and many people use the HotSync Option. Palm has instructed us to simply disable the HotSync manager software. In some cases, you will be required to remove the software entirely. If you find this to be the case, please contact Palm support for further assistance: http://www.palm.com/support

*Handspring is another very common PDA terminal, Handspring does have support options in their software to choose either just the USB connection, or the specific COM port that the Cradle is plugged in. Please contact Handspring at: http://support.handspring.com

*Another common culprit for problems using a free serial port is Powerchute software for uninterruptible power supplies (UPS). The most common of these is APC; they have informed us that their software options, if installed, will lock any virtual port associated to the COM port in use. In other words if you use COM1 you will not be able to use COM3, or visa versa. If you are using COM2 you cannot use COM4, or visa versa. For further information on this subject, please contact APC or your UPS manufacturer: http://www.apc.com/support/index.cfm

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[[Category:troubleshooting]]