182
•
Fieldbus Communication
ETHERNET
WAGO-I/O-SYSTEM
750
BACnet/IP Controller
Gateway
The subnets of the Internet are normally connected via gateways. The function
of these gateways is to forward packets to other networks or subnets.
This means that in addition to the IP address and network mask for each net-
work card, it is necessary to specify the correct IP address of the standard
gateway for a PC or fieldbus node connected to the Internet. You should also
be able to obtain this IP address from your network administrator.
The IP function is limited to the local subnet if this address is not specified.
IP Packet
In addition to the data units to be transported, the IP data packets contain a
range of address information and additional information in the packet header.
IP-Header
IP-Data
Fig. 4-11: IP Packet
The most important information in the IP header is the IP address of the trans-
mitter and the receiver and the transport protocol used.
