User`s manual

NPort 6000 Series User’s Manual Configuring Serial Port Operation Modes
7-17
1200 bps, 8 data bits, 1 stop bit, and no parity. In this case, the total number of bits needed to send
a character is 10 bits, and the time required to transfer one character is
(10 (bits) / 1200 (bits/s)) × 1000 (ms/s) = 8.3 ms.
Therefore, you should set the force transmit time to be larger than 8.3 ms, so in this case, it must
be greater than or equal to 10 ms.
If it is necessary to send a series of characters in the same packet, the serial device will need to
send that series of characters within the specified force transmit time, and the total length of data
must be less than or equal to the NPort 6000’s internal buffer size (1 KB per port).
Pair Connection Mode
Pair Connection mode can be used to remove the 15-meter distance limitation imposed by the
RS-232 interface. It establishes a connection between a serial port on one NPort 6000 server and
another serial port on another NPort 6000 server. One of the serial ports is connected to the COM
port of a PC or another type of computer, such as a hand-held PDA that has a serial port. The other
serial port is connected to the desired serial device. The two NPort 6000 servers are then connected
to each other with a crossover Ethernet cable, and both are connected to the same LAN. In a more
advanced setup, the two NPort 6000 servers communicate with each other over a WAN (i.e.,
through one or more routers). In Pair Connection Mode, both data and modem control signals (but
not DCD signals) are transparently transferred between the two NPort 6000 servers.
Pair Connection Master Mode
When using Pair Connection mode, Pair Connection Master mode must be selected as the
Operation mode for one of the two serial ports involved, and Pair Connection Slave mode must be
selected for the other serial port. In effect, the serial port that is in Pair Connection Master mode
will be acting as a TCP client and the one that is slave mode will be acting as a TCP server. In
practice, it does not matter which port is the master and which port is the slave.
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 even if there is no response to the “keep alive” packets.
Secure (default=No): If you select Ye s , data sent through the Ethernet will be encrypted with SSL.