GE D30 Instruction Manual page 161

CHAPTER 5: SETTINGS PRODUCT SETUP
— This setting specifies the minimum time before the rear RS485 port transmits after
RS485 COM2 RESPONSE MIN TIME
receiving data from a host. This feature allows operation with hosts that hold the RS485 transmitter active for some time
after each transmission.
5.3.4.3 Ethernet network topology
The D30 has three Ethernet ports. Each Ethernet port must belong to a different network or subnetwork. Configure the IP
address and subnet to ensure that each port meets this requirement. Two subnets are different when the bitwise AND
operation performed between their respective IP address and mask produces a different result. Communication becomes
unpredictable when more than one port is configured to the same subnet.
Example 1
IP1/Mask1: 10.1.1.2/255.255.255.0 (where LAN 1 is 10.1.1.x/255.255.255.0)
IP2/Mask2: 10.2.1.2/255.255.255.0 (where LAN2 is 10.2.1.x/255.255.255.0)
IP3/Mask3: 10.3.1.2/255.255.255.0 (where LAN3 is 10.3.1.x/255.255.255.0)
Example 2
IP1/Mask1: 10.1.1.2/255.0.0.0 (where LAN1 is 10.x.x.x/255.0.0.0)
IP2/Mask2: 11.1.1.2/255.0.0.0 (where LAN2 is 11.x.x.x/255.0.0.0)
IP3/Mask3: 12.1.1.2/255.0.0.0 (where LAN3 is 12.x.x.x/255.0.0.0)
Example 3 — Incorrect
IP1/Mask1: 10.1.1.2/255.0.0.0 5
IP2/Mask2: 10.2.1.2/255.0.0.0
IP3/Mask3: 10.3.1.2/255.0.0.0
This example is incorrect because the mask of 255.0.0.0 used for the three IP addresses makes them belong to the same
network of 10.x.x.x.
Single LAN, no redundancy
The topology shown in the following figure allows communications to SCADA, local configuration/monitoring through
EnerVista, and access to the public network shared on the same LAN. No redundancy is provided.
D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL 5-29