User's Manual

NPort W2150A/W2250A Series Installing and Configuring the Software
11-9
3. On the Advanced Setting tab, configure Tx Mode, FIFO, and Fast Flush.
Tx Mode: In Hi-Performance mode, the driver immediately issues a “Tx Empty” response to the program
after sending data to the NPort. In Classical mode, the driver sends the “Tx Empty” response after
confirmation is received from the NPort. Classical mode is recommended if you want to ensure that all data
is sent out before further processing.
FIFO: This tells the driver whether or not to use the FIFO.
Network Timeout: You can use this option to prevent blocking if the target NPort is unavailable.
Fast Flush: When enabled, the driver flushes only the local buffer on the host for a Win32 PurgeComm()
function call. When disabled, both the local and remote buffers are flushed. If your application uses
PurgeComm() and performance seems sluggish, try enabling Fast Flush.
Auto Network Re-Connection: With this option enabled, the driver will repeatedly attempt to
re-establish the TCP connection if the NPort does not respond to background “check alive” packets
Always Accept Open Requests: When enabled, the NPort driver will always accept requests to open a
virtual COM port, even if communications with the device can not be established. With this option, the NPort
driver will agree to open a virtual COM port on the system even if the port is blocked or the Ethernet
connection is disabled. If this is the case, the connected device will not receive and transmit data even
though the system has opened a virtual COM port.
Drop Writing Data if Network Connection is Lost: This function will assure the data to be kept in the
buffer or dropped when network connection is lost. The buffer size is 4 KBytes.
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 NPort. 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 NPort. 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