Fieldbus
Communication
•
181
ETHERNET
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
The standard masks depending upon the respective network class are as fol-
lows:
Class A Subnet mask:
255
.
0
.
0
.
0
Class B Subnet mask:
255 .255 .0 .0
Class C Subnet mask:
255
.
255
.
255
.
0
Depending on the subnet division the subnet masks may, however, contain
other values beyond 0 and 255, such as 255.255.255.128 or 255.255.255.248.
Your network administrator allocates the subnet mask number to you.
Together with the IP address, this number determines which network your PC
and your node belongs to.
The recipient node, which is located on a subnet initially, calculates the cor-
rect network number from its own IP address and the subnet mask.
Only then does it check the node number and delivers the entire packet frame,
if it corresponds.
Example of an IP address from a class B network:
IP address:
172.16.233.200
10101100 00010000 11101001 11001000
Subnet mask:
255.255.255.128
11111111 11111111 11111111 10000000
Net-ID:
172.16.00
10101100 00010000 00000000 00000000
Subnet-ID:
0.0.233.128
00000000 00000000 11101001 10000000
Host-ID:
0.0.0.72
00000000 00000000 00000000 01001000
Attention
Specify the network mask defined by the administrator in the same way as the
IP address when installing the network protocol.
