WAGO 750-341, Manual

Page: 119 / 246

Fieldbus Communication • 113
ETHERNET
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP
4.1.3.4.3 DHCP (Dynamic Host Configuration Protocol)
The coupler’s/controller’s built-in HTML pages provide an option for IP
configuration from a DHCP server, a BootP server, or the data stored in its
EEPROM by default.
Note
The network configuration via DHCP is not stored in the EEPROM, this only
occurs when using the BootP protocol.
The DHCP client allows dynamic network configuration of the
coupler/controller by setting the following parameters:
Parameter Meaning
IP address of the client Network address of the coupler/controller
IP address of the
router If communication is to take place outside of the local network,
the IP address of the routers (gateway) is indicated in this
parameter.
Subnet mask The Subnet mask makes the coupler/controller able to
differentiate, which parts of the IP address determine the
network and which the network station.
IP addresses of the
DNS servers Here the IP addresses can be entered by maximally 2 DNS
servers.
Lease time Here the maximum duration can be defined, how long the
coupler/controller keeps the assigned IP address. The maximum
lease time is 24.8 days. This results from the internal resolution
of timer.
Renewing time The Renewing time indicates, starting from when the
coupler/controller must worry about the renewal of the leasing
time.
Rebinding time The Rebinding time indicates, after which time the
coupler/controller must have gotten its new address.
In the case of configuration of network parameters via the DHCP protocol, the
coupler/controller automatically sends a request to a DHCP server after
initialisation. If there is no response, the request is sent again after 4 seconds,
a further one after 8 seconds and again after 16 seconds. If all requests remain
unanswered, a blink code is output via the “IO” LED. Transfer of the
parameters from the EEPROM is not possible.
Where a lease time is used, the values for the renewing and rebinding time
must also be specified. After the renewing time expires, the coupler/controller
attempts to automatically renew the lease time for its IP address . If this
continually fails up to the rebinding time, the coupler/controller attempts to
obtain a new IP address. The time for the renewing should be about one half
of the lease time. The rebinding time should be about
7
/
8
of the lease time.