VTI Instruments Ametek EX1200A Series, User Manual

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VTI Instruments Corp.
130 EX1200A Web Page Operation
N
ETWORK
C
ONFIGURATION
The EX1200A Network Configuration page can be seen in Figure 7-15. By default, the
EX1200A will attempt to locate a DHCP server. If one is found, the IP address assigned by the
DHCP server will be assumed, along with subnet masks, gateway, etc. Otherwise, after a timeout
of 20 seconds, the unit will attempt to obtain an IP address by using Auto IP (IPv4 Dynamic Link
Local Addressing).
NOTE The EX1200A can be returned to a known, default network configuration by using the LCI (LAN
Configuration Initialize) Mechanism. See
Reset Button for more information.
Auto IP is a mechanism for finding an unused IP address in the IANA assigned range
169.254.X.Y (169.254/16) where X is in the range 1 to 254 and Y is in the range 0 to 255. The
device will first attempt to obtain the specific address 169.254.X.Y, where X and Y are the
second-to-
last and last octets of the device’s MAC address
. However, X will be set to 1 if it is 0 in
the MAC address, and to 254 if it is 255 in the MAC address for conformance with the Auto IP
specifications. If this address is already in use, the unit will attempt to obtain other IP addresses in
the 169.254/16 range in a pseudorandom fashion until it finds one that is available.
To illustrate the Auto IP mechanism, Table 7-1 lists the Auto IP default address for some example
MAC addresses.
MAC Address Auto IP Default Address
00:0D:3F:01:00:01 169.254.1.1
00:0D:3F:01:01:01 169.254.1.1
00:0D:3F:01:A3:28 169.254.163.40
00:0D:3F:01:FE:FE 169.254.254.254
00:0D:3F:01:FF:FE 169.254.254.254
T
ABLE
7-1: A
UTO
IP D
EFAULT
A
DDRESS
A
SSIGNMENT
If a static IP address assignment is preferred, one can be optionally assigned via the embedded
web page interface. This is done by clicking the Network Configuration link, disabling DHCP and
Auto IP, enabling Static, and then assigning a static IP address, subnet mask, and gateway address,
and, optionally, up to three DNS servers (see Figure 7-15).
NOTE The 169.254/16 subnet is reserved by the IANA for Auto IP usage. It should not be used for either
DHCP or static IP configurations.
However, a much more convenient and recommended way to obtain the benefits of a static IP
address is to employ DHCP, but assign the instrument a reserved IP address in your company’s
DHCP server configuration. This reserved address, linked to the EX1200A
’s MAC address on the
DHCP server, would be assigned to the EX1200A at power up initialization without having to
manually set it on the EX1200A. The DHCP server configuration provides a centralized,
controlled database of assigned IP addresses, preventing accidental assignment of the same IP
address to multiple instruments. Consult your company’s Information Technology department for
assistance.
VXI-11 Device Discovery is also supported by the EX1200A. This allows all EX1200As on a
local network to be found without knowledge of their MAC address or IP address with the use of a
broadcast message.
Should problems arise with network configuration, please refer to Network Troubleshooting in
Section 2 for assistance.