📖HomeBack When using a Comtrol Rocketport serial port card from within ClearSCADA, the ports may fail displaying the "No Write in Progress" error in the alarm list.
ClearSCADA drivers require the "Wait on physical transmission before completing write" to be enabled on the Comtrol drivers to work correctly. If this is not checked the Comtrol driver will send two write completion notification, one when it accepts the write and the second when the transmit actually completes. This confuses the ClearSCADA drivers and the error "No Write in Progress" is displayed.
For these systems it may be worth installing the most up to date drivers from http://support.comtrol.com/download as the drivers available on the web site are often more up to date than those shipped with the product. A PC reboot after making changes to the Comtrol settings is recommended as the setting changes are not always dynamic (even if they do not prompt for a reboot).