GE GFK-1541B manual Module Configuration for the Ethernet Interface in PLC B

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However, if you configure a routing table for PLCs B and C, their data may be forwarded to other gateways. If Gateway G1 has been configured as the default gateway, the routing table could have an entry for Subnet 2.2 via Gateway G2 and Subnet 2.3 via Gateway G3. If the data is not destined for either remote Subnet 2.2 or Subnet 2.3, then the data would be routed to Gateway G1, the default gateway.

To configure a PLC on Subnet 2.1 to be able to communicate with Network 1, Subnet 2.2, and Subnet 2.3 you need to know the following information.

Address of Gateway (G1)	172.17.64.3 (Default Gateway)
Subnet Mask for Subnet 2.1:	255.255.192.0
Address of Gateway (G2)	172.17.64.4
Subnet Mask for Subnet 2.2:	255.255.192.0
Subnet ID of Subnet 2.2*:	172.17.128.0
Address of Gateway (G3)	172.17.64.5
Subnet Mask for Subnet 2.3:	255.255.192.0
Subnet ID of Subnet 2.3*:	172.17.192.0

*The subnet ID is derived by ANDing the bits of the subnet mask and an IP address on the destination subnet.

Module Configuration for the Ethernet Interface in PLC B

The IP address, subnet mask, and default gateway IP address are entered in the Ethernet

Interface’s module configuration.

IP Address: 172.17.64.1

Subnet Mask: 255.255.192.0

Default Gateway IP Address: 172.17.64.3

PLC Routing Table to Configure Multiple Gateways for PLC B and PLC C

The following routing table entries are entered into the PLC’s Routing tab of the Name Resolution and Routing Tables Rack Operation via the Windows-based PLC programming software (if supported).

# Destination Subnet ID Destination Subnet Mask

Next Hop IP Address (Gateway IP Address)

Cost

1	172.17.128.0	255.255.192.0	172.17.64.4	1
2	172.17.192.0	255.255.192.0	172.17.64.5	1

6-8 TCP/IP Ethernet Communications for the Series 90™ PLC User's Manual– May 2002 GFK-1541B