Thermo Scientific APEX 100, User Manual

Page: 329 / 442

Thermo Scientific APEX User’s Guide
Page 329
Changing the DHCP Default Setting During Installation
The default setting for DHCP is “on” (as shown by the check mark next to the function).
Because the DHCP setting is set—by default—to “on,” a network host-device will set the
IP, subnet-mask, gateway, and MAC addresses for you when you do either of the
following.
• Scenario 1—Powering up the APEX for the first time after installing the Modbus
card.
•
Scenario 2—Powering down the APEX (for example, by turning it off at night) and
powering it up again (for example, by restarting the APEX in the morning).
It is scenario 2 that sometimes causes a problem, because the network may assign new
addresses to the APEX, leading to network problems. Thus, if you constantly power
down and power up the APEX, it is best to let the network assign the addresses when
you first install the Modbus card (scenario 1), and then change the DHCP setting to “off”
to lock in these addresses. Then, during subsequent power ups and downs (scenario 2),
a network device cannot change these addresses, eliminating potential network
problems for the APEX.
Changing DHCP to “Off”
To change the DHCP setting to “off” (and lock in your current IP, subnet-mask, and
gateway addresses), do the following.
1)
Make sure the DHCP function is highlighted. (The check mark indicates that DHCP is
currently set to its default value, “on.”)
Dynamic Host Control Protocol
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