Auto Network Re-Connection
With this option enabled, the driver will repeatedly attempt to re-establish the TCP connection if the CN2600
does not respond to background “check alive” packets.
Return error if network is unavailable
If this option is disabled, the driver will not return any error even when a connection cannot be established to
the CN2600. With this option enabled, calling the Win32 Comm function will result in the error return code
“STATUS_NETWORK_UNREACHABLE” when a connection cannot be established to the CN2600. This usually
means that your host’s network connection is down, perhaps due to a cable being disconnected. However, if
you can reach other network devices, it may be that the CN2600 is not powered on or is disconnected. Note that
Auto Network Re-Connection must be enabled in order to use this function.
Fast Flush (only flushes the local buffer)
For some applications, the user’s program will use the Win32 “PurgeComm()” function before it reads or writes
data. After a program uses this PurgeComm() function, the CN2600 driver will continue to query the CN2600
firmware several times to make sure no data is queued in the CN2600 firmware buffer, rather than just flushing
the local buffer. This design is used to satisfy some special considerations. However, it may take more time (on
the order of several hundred milliseconds) than a native COM1 due to the additional time spent communicating
across the Ethernet. This is why PurgeComm() works significantly faster with native COM ports on the PC than
with mapped COM ports on the CN2600. In order to accommodate other applications that require a faster
response time, the new CN2600 driver implements a new Fast Flush option. By default, this function is enabled.
If you have disabled Fast Flush and find that COM ports mapped to the CN2600 perform markedly slower than
when using a native COM port, try to verify if “PurgeComm()” functions are used in your application. If so, try
enabling the Fast Flush function and see if there is a significant improvement in performance.
10. The Serial Parameters page shown in the following figure shows the default settings when the CN2600 is
powered on. However, the program can redefine the serial parameters to different values after the program
opens the port via Win 32 API.
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