When I use Docklight V2.3 with my COM device, I receive periodic error messages “Docklight reports: General I/O error on COM…”. In Docklight V2.2 this does not happen. How can I make Docklight V2.3 work with my device?

When I use Docklight V2.3 with my COM device, I receive periodic error messages “Docklight reports: General I/O error on COM…”. In Docklight V2.2 this does not happen. How can I make Docklight V2.3 work with my device?

Applies to: Docklight / Docklight Scripting V2.3, Article ID: dl_prb055

Docklight V2.3 introduced additional error checking which seems to cause problems with some very few COM devices. The V2.4 versions contain some refinements and allows to disable the error check completely:

* Install the relevant update from the links below.

* Check if the problem still persists.

* If necessary, use menu Tools | Expert Options… , go to the “Devices” tab, and activate the “Disable I/O error detection…” checkbox.

Background:

In Docklight V2.3, we changed the way the COM port RX/TX code reacts to any error from Windows “overlapped I/O”. Docklight V2.2 simply ignored such errors. This meant that V2.2 (or earlier) could not detect or recover from hotplug/replug situations with USB-to-RS232 converters. Docklight V2.3 reports such errors and tries to re-connect to the device, allowing you to unplug a USB-to-RS232 dongle, plug it back, and after a few seconds, Docklight will continue to communicate. The same is true for notebook standby/resume situations.

After the V2.3 release we have seens some isolated COM device drivers that always produce such I/O errors, even in normal operation. They were fine to use with Docklight V2.2, but in V2.3 this was not possible.

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