Address Routing Table; Passthru Feature - Allen-Bradley SLC 500 Quick Start Manual

Passthru Feature

This chapter contains information about the new passthru feature on
SLC 5/05 (1747-OS501, FRN 3) processors, including:
Updated status file information
Error code information
An example of DF1-to-Ethernet and Ethernet-to-DF1 routing
An example of DH485-to-Ethernet and Ethernet-to-DH485
routing
This feature permits an SLC 5/05 processor to act as a bridge,
allowing communication data packets to be passed between the
RS232 serial port (Channel 0) and the Ethernet port (Channel 1).
This RS232-to-Ethernet bridge operates only when the RS232 serial
port is configured for DF1 full-duplex communication or DH485
communication.
A maximum of 128 Ethernet devices may be accessed using the
passthru feature.
Important:
For 1747-OS501 support, use RSLogix Rev. 2.51.0 or
higher, and RSLinx Rev. 1.70.62 or higher.

Address Routing Table

To enable passthru of data packets between the RS232 port and the
Ethernet port, the SLC 5/05 processor uses a routing table to
cross-reference the one-byte addressing used by DF1 and DH485
protocols with the four-byte IP address needed to support Ethernet
communication. The routing table is stored in a user-selectable
integer file and uses two word elements of the integer file to store
one IP address. The routing table file number must be between 9 and
255. The routing table must be at least two words in length.
Publication 1747-10.4