User's Manual

NPort W2150A/W2250A Series Introduction to Operation Modes
4-3
ATTENTION
In
RealCOM
mode, several hosts can have simultaneous access control over the NPort serial port. If necessary,
you can limit access by using the NPort’s Accessible IP settings. Pl
ease refer to Chapter 8 for additional
information on Accessible IP settings.
RFC2217 Mode
RFC-2217 mode is similar to RealCOM mode, since it relies on a driver to transparently map a virtual COM port
on a host computer to a serial port on the NPort. The RFC2217 standard defines general COM port control
options based on the Telnet protocol and supports one connection at a time. Third party drivers supporting
RFC-2217 are widely available on the Internet and can be used to implement virtual COM mapping.
TCP Server Mode
In TCP Server mode, the NPort serial port is assigned
an IP:port address that is unique on your TCP/IP
network. It waits for the host computer to establish a
connection to the attached serial device. This
operation mode also supports up to
eight
simultaneous connections, so multiple hosts can
collect data from the attached device at the same
time.
Data transmission proceeds as follows:
A host requests a connection to the NPort serial port.
Once the connection is established, data can be
transmitted in both directions
—from the host to the
device, and from the device to the host.
TCP Client Mode
In TCP Client mode, the NPort actively establishes a
TCP connection to a specific network host when data
is received from the attached serial device. After the
data has been transferred, the NPort can
automatically disconnect from the host computer
through the Inactivity time settings. Please refer to
Chapter 7 for details on these parameters.
Data transmission proceeds as follows:
The NPort reque
sts a connection from the host.
The connection is established and data can be
transmitted in both directions between the host and
device.