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 provides additional error checking which seems to cause problems with some very few COM devices. V2.4 contains 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 could not detect or recover from hotplug/replug situations with USB-to-RS232 converters. Docklight V2.3 reports 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. The below updates address this problem.

NOTE: The problem also appears when using Docklight with WineHQ on Linux, as described in the link below.

Docklight V2.4 Preview (expert option: i/o errors)

Docklight Scripting V2.4 Preview (expert option: i/o errors)

Docklight News – RS232 / tty testing and simulation on Linux