Delta RMC151 - Manual (Page 448)

RMC70/150 and RMCTools User Manual
Example:
The user decided to use the 192.168.0 address. Because this network address is 24 bits
long, the subnet mask will be 255.255.255.0. This leaves 254 local addresses
(remember that addresses 0 and 255 are reserved) for an IP address range of
192.168.0.1 to 192.168.0.254.
3. Assign local addresses for each device.
The IP address range from step 2 provides 254 IP addresses that can be assigned to
the network devices. When assigning addresses, ensure that all devices have unique
address. To avoid assigning the same IP address twice, record the IP address
assignments for use later when you need to add or replace device.
By convention, local address 1 (IP address 192.168.0.1 in our new example network in
the previous step) is used as the default gateway. Even if you do not have
gateway/router, it is a good idea to leave that address unassigned. Assign your first
device (perhaps a PLC) 192.168.0.2, assign your second device (perhaps an RMC)
192.168.0.3, etc.
4. Enter the network parameters into each device.
The method of assigning the network parameters varies for each type of device. Use
the IP address you have assigned, a subnet mask of 255.255.255.0, and leave the
default gateway blank for each device. See RMC Ethernet Setup for details on editing
these parameters on the RMC, and consult the manuals of the other devices on your
network for details on setting up their TCP/IP parameters.
6.8.9.2. Understanding Ethernet IP Addressing
IP Address
A fundamental part of setting up a TCP/IP network is setting up IP addresses. An IP
address is a 32-bit number that is generally displayed in dotted decimal format, in which
each octet (8 bits) of the address is displayed in decimal format, and each value is
separated by period (e.g. 192.168.0.5). A less common, but often useful, way of
displaying the address is in hexadecimal. The hexadecimal equivalent of 192.168.0.5 is
C0A80005. Every computer on an intranet (one or more networks connected together)
must have a unique IP address.
Subnet Mask
To facilitate communicating between multiple interconnected networks, the IP address is
broken into two parts. One part is the network address, and the other part is the local
address. Each network has a unique network address, and every device on that network
has the same network address portion in its IP address. The local address uniquely
identifies a computer within a network. It is expected that local addresses will be
duplicated on different networks, but the entire IP address (network address + local
address) is always unique.
The method for determining which portion of the IP address is the network address and
which portion is the local address is to use a value called a subnet mask. A subnet mask
is also a 32-bit number often displayed in dotted decimal format. Each bit of the subnet
mask that is a 1 means that the corresponding bit of the IP address is part of the network
address. Each bit of the subnet mask that is a 0 means that the corresponding bit of the
IP address is part of the local address.
Example:
Decimal Value Hexadecimal
428 Delta Computer Systems, Inc.