188
•
Fieldbus Communication
ETHERNET
WAGO-I/O-SYSTEM
750
BACnet/IP Controller
In the case of configuration of network parameters via the DHCP protocol, the
coupler/controller automatically sends a request to a DHCP server after ini-
tialization. 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 parame-
ters 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 con-
tinually 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.
4.1.3.3.4
DNS (Domain Name Systems)
The DNS client enables conversion of logical Internet names such as
into the appropriate decimal IP address represented with
separator stops, via a DNS server. Reverse conversion is also possible.
The addresses of the DNS server are configured via DHCP or web-based man-
agement. Up to 2 DNS servers can be specified. The host identification can be
achieved with two functions, an internal host table is not supported.
4.1.3.3.5 SNTP-Client
(Simple Network Time Protocol)
The SNTP client is used for synchronization of the time of day between a time
server (NTP and SNTP server Version 3 and 4 are supported) and the clock
module integrated in the (programmable) fieldbus coupler or controller. The
protocol is executed via a UDP port. Only unicast addressing is supported.
Configuration of the SNTP client
The configuration of the SNTP client is performed via the web-based man-
agement system under the “Clock” link. The following parameters must be
set:
Parameter
Meaning
Address of the
Time server
The address assignment can be made either over a IP address or a host
name.
Time zone
The time zone relative to GMT (Greenwich Mean time). A range of -
12 to +12 hours is acceptable.
Update Time
The update time indicates the interval in seconds, in which the syn-
chronization with the time server is to take place.
Enable Time
Client
It indicates whether the SNTP Client is to be activated or deactivated.
