User`s manual

NPort 6000 Series User’s Manual Configuring Serial Port Operation Modes
7-3
Device Control Applications
Real COM Mode
TCP alive check time (default=7 min): This field specifies how long the NPort 6000 will wait for
a response to “keep alive” packets before closing the TCP connection. The NPort 6000 checks
connection status by sending periodic “keep alive” packets. If the remote host does not respond to
the packet within the time specified in this field, the NPort 6000 will force the existing TCP
connection to close. For socket and device control modes, the NPort 6000 will listen for another
TCP connection from another host after closing the connection. If TCP alive check time is set to 0,
the TCP connection will remain open and will not send any “keep alive” packets.
Max connection (default=1): This field is used if you need to receive data from different hosts
simultaneously. When set to 1, only one specific host can access this port of the NPort 6000, and
the Real COM driver on that host will have full control over the port. When set to 2 or greater, up
to the specified number of hosts’ Real COM drivers may open this port at the same time. When
multiple hosts’ Real COM drivers open the port at the same time, the COM driver only provides a
pure data tunnel—no control ability. The serial port parameters will use firmware settings instead
of depending on your application program (AP).
Application software that is based on the COM driver will receive a driver response of “success”
when the software uses any of the Win32 API functions. The firmware will only send data back to
the driver on the host.
Data will be sent first-in-first-out when data comes into the NPort 6000 from the Ethernet
interface.