If you're trying to interface your Timing Console to Meet Manager and you got an Error 8020 / 8021 (error reading com device), it means driver for USB-to-serial adapter is not installed correctly or is not up to date

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Option 1: Contact manufacturer to obtain updated driver
Option 2: Purchase different USB-to-serial adapter with alternate driver
 
Note: Problem is known to occur with some third-party serial drivers
 
A serial driver should return SUCCESS synchronously for all read requests that can be immediately fulfilled with data that is currently present