Chapter 6
Using Your Serial Device Server
©
National Instruments Corporation
6-3
ENET-232 and ENET-485 Series User Manual
table. Alternately, you can use NI Ethernet device configuration to
determine the hostname associated with your assigned IP address, and
change the hostname to match the DNS entry. Refer to the
section in Chapter 3,
, for more
information.
Because there are many other possible reasons for failure, contact your
network administrator if you are having problems getting DHCP to work.
When you can use DHCP and DNS successfully, you can use the hostname
form of the IP address to communicate with your product—even if the
numerical IP address changes with successive reboots.
If you are setting up a small network for your instrumentation system,
National Instruments recommends using static IP addresses, because they
are easier to implement and maintain. In this system, you can safely use the
numerical form of the IP address to communicate with your product
because the address is unlikely to change. Small networks are less likely to
have domain name services available that would resolve the hostname into
a numerical IP address.
Using the CFG RESET Switch
The Configuration Reset (CFG RESET) switch is a recessed switch beside
the Ethernet (ENET) connector on the rear panel. Refer to Figure 2-2,
Panel of a Four-Port Serial Device Server
, for an illustration of its location.
This switch performs two functions, depending on whether you press it at
power-on or during operation.
Using the CFG RESET Switch
D
uring Operation
While the serial device server is operational, as indicated by a steady
yellow
PWR/RDY
LED, you can use the CFG RESET switch to place the
box into network configuration mode.
This special mode ensures that network parameters are not changed while
in normal operation mode. Because you cannot change the network
parameters unless you deliberately place the serial device server into
network configuration mode, the parameters are protected while in normal
operation. Hosts cannot connect to the serial device server while it is in
network configuration mode.
Note
Pressing the CFG RESET switch has no effect if hosts are currently connected.
