Metrohm NIRS XDS Transmission OptiProbe Analyzer - Manual (Page 13)

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can only be entered by an authorized user, using the “two-token” method of entry. (Unique
User ID and password)
3. 3. Upon being powered up on a LAN, the XDS instrument requests a “dynamic” IP address
from the DHCP server which controls the LAN. This IP address is normally granted promptly
(typically in 5-10 seconds) so the instrument can function on the LAN. Most DHCP servers
track the XDS instrument by the “MAC” (Machine Access Code) to later re-assign that same IP
address whenever the XDS instrument is on the LAN.
4. 4. If there is no DHCP server available to assign an IP address (a free-standing router may
serve the same DHCP function), the XDS instrument will “time out” in 45 seconds --and it will
know that it is not attached to an active LAN. It will then default to an internally-stored
default IP address. This address, 169.254.0.2, is used for local, free-standing communication
only. In such cases, a crossover cable, or a hub with two patch cables, should be used to
connect the computer and the XDS instrument.
5. 5. Upon the next power-down and subsequent power-up of the XDS instrument, it will again
request an IP address of the DHCP server. It will go through the same cycle, eventually
reverting to the stored default IP address. This is intentional.
6. 6. A dynamic IP address is the preferred method of XDS instrument connection. The default IP
address is only used when no DHCP server is available to assign a dynamic IP address.
A short glossary of terms follows. See the flowchart diagram for XDS instrument communication
which visually outlines the items explained above.
3.2.2 Flowchart Diagram of XDS communication protocol
3.2.3 Microsoft Windows Firewalls