Rockwell Automation 1785-ENET USER MANUAL PLC-5 ETHERNET INTERFACE - Manual (Page 28)

1785-6.5.19 November 1998
3-4 Configuring the Interface Module for Ethernet Communication
Using BOOTP to Enter Configuration Information
BOOTP is a protocol that supplies the interface module with
configuration information at power-up. BOOTP lets you dynamically
assign IP addresses to devices on the Ethernet link.
To use BOOTP, a BOOTP server must exist on the local Ethernet
subnet. The server is a computer (either a personal computer, VAX, or
UNIX system) that has BOOTP-server software installed and reads a
text file containing network information for individual nodes on
the network.
To enable BOOTP, follow the steps specified in your programming
software documentation to specify Ethernet configuration
information. See the table on page 3-3 for field descriptions.
When BOOTP is enabled, the following events occur at power-up:
• The processor broadcasts a BOOTP-request message containing
its hardware address over the local network or subnet.
• The BOOTP server compares the hardware address with the
addresses in its look-up table in the BOOTPTAB file.
• The BOOTP server sends a message back to the processor with
the IP address and other network information that corresponds to
the hardware address it received.
With all hardware and IP addresses in one location, you can easily
change IP addresses in the BOOTP configuration file if your network
needs change.
Edit the BOOTPTAB Configuration File
Important: Be sure you know the Ethernet hardware address of the
module. You will enter it in this file.
You must edit the BOOTPTAB file, which is an ASCII text file, to
include the name, IP address, and hardware address for each Ethernet
interface module you want the server to boot. To edit this file:
1. Open the BOOTPTAB file using a text editor.
• The file contains lines that look like this:
#Default string for each type of Ethernet client
defaults5E: ht=1:vm=rfc1048
These are the default parameters for Ethernet PLC-5 interface
module and must always precede the client lines in the
BOOTPTAB file.
• The file also contains a line that looks like this:
sidecar: tc=default5E:ip=aa.bb.cc.dd:ha=0000BC03xxyy
Important: Use this line as the configuration template for
Ethernet devices.
Be sure you have assigned a diagnostics file in which
to store channel status information.
See an example of a BOOTPTAB file on the page 3-6.