Rockwell Automation 1753-PCS-PAR Using RSLogix Guard PLUS! with GuardPLC Controllers - Manual (Page 13)

Publication 1753-PM001A-EN-P - November 2005
Connect to the GuardPLC Controller 1-3
(octets 001 and 002) and the Host ID (octets 003 and 004). The
Network ID portion of the IP address is derived from the subnet mask.
When any two devices attempt to talk on Ethernet, a check is made to
see if the Network ID of both the originator and the destination
address match. If they match, then the message is sent on the local
network. If they do not match, then the message is sent to the
Gateway to route the message to the destination. The subnet masks of
all the devices on a local network should be the same.
The example below illustrates how to derive the Network ID based on
the GuardPLC controller’s IP address and subnet mask defaults.
Configure the IP Address of Your Programming Terminal
EXAMPLE
Determine the Network ID
Default Settings:
IP Address 192.168.0.99
= 11000000 . 10101000 . 00000000 . 01100011
Subnet Mask 255.255.252.0 = 11111111 . 11111111 . 11111100 . 00000000
Network ID
= 11000000 . 10101000 . 000000xx . xxxxxxxx
Set up the programming terminal’s IP address so that it has the same Network ID as
the GuardPLC controller. Octets one and two have to be the same because the
subnet mask octets are 255. The third subnet mask octet is 252, which means that
only the last two bits can be different.
If the factory default settings above are used, the allowable IP addresses for the
programming terminal running RSLogix Guard PLUS! software are:
• 192.168.0.xxx (xxx represents any value between 000-255)
• 192.168.1.xxx
• 192.168.2.xxx
• 192.168.3.xxx
IMPORTANT
The first time you connect to a controller, you must
use the factory-set IP address of 192.168.0.99 and the
default SRS of 60000. After you establish
communications with the controller (using the steps
on the following pages), you can change the IP
address and SRS to better accommodate your
Ethernet network.