Technical data

142
W&T
7 Appendix
7.1 Alternative IP address assigning
7.1.1 ... using DHCP-/BOOTP protocol
Many networks use DHCP (Dynamic Host Configuration
Protocol) or BOOTP for centralized and dynamic assignment of
the IP addresses. Which of the two protocols is used in any in-
dividual situation makes no difference with respect to Web-IO
devices, since DHCP is simply a downward compatible
expansion of BOOTP. DHCP servers thus use the same requests
as BOOTP clients.
The following parameters can be assigned to the Web-IO Ana-
log using these protocols:
■ IP address
■ Subnet mask
■ Gateway address
Function
To obtain an IP address the device sends a corresponding
BOOTP request as a broadcast to the network after each restart.
The resulting reply generated by the DHCP/BOOTP server
contains along with the IP address the subnet mask and
gateway address. The Web-IO immediately copies this
information to its non-volatile memory.
When starting up the device in DHCP/BOOTP networks, contact
the responsible system administrator. If using DHCP for
address assignment, you must also make it clear that a
reserved IP address is required. To incorporate this into the
respective address database, the administrator needs the
Ethernet address of the Web-Graph Thermometer, which can be
found on the housing sticker.
After the necessary entries have been made, the device
automatically obtains the desired IP address after each reset.