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How to communicate with PowerLogic or Modbus devices on an isolated Ethernet network using EGX gateways.

Issue
How can 2 PC's on isolated ethernet networks both communicate to a daisy chain of PowerLogic or Modbus devices that are connected to an EGX200 or EGX400.

Product Line
EGX200, EGX400, EGX100, EGX300

Environment
Communications connections on isolated networks

Resolution
The goal is to establish communications from 2 PC's to a daisy chain of PowerLogic or Modbus devices that are connected to an EGX200 or EGX400. The EGX is on an isolated Ethernet network (Network A). One PC is on network A and the other PC is on network B. Both PC's are physically connected to separate Ethernet segments. This set of instructions and diagram will explain how this can be accomplished with the use of an additional EGX100/300

Network A is the isolated PowerLogic network. In this example it consists of a computer, EGX200, and two Circuit Monitors/Power Meters.

Network B is on a completely different network.

Network A:
The Circuit Monitor (CM) and Power meter (PM) are connected on a daisy chain (RS485) from the COM1 port of the EGX200.
The EGX200 will hold the device list and addresses of the connected devices of Network A.


Network B:
An EGX100 is used to bridge the two networks together.
No Modbus addresses or devices should be added to the EGX-100 setup tables.


Both networks:
From the EGX100, a RS485 connection is made to the COM2 port of the EGX200 on Network A.

Note: The RS485 wires must be crossed from the EGX100 to the EGX200 (transmit to receive, receive to transmit). Refer to the diagram for connections.
The RS485 comm port settings should be configured the same on both EGX's. (baud rate, parity, 4 wire)

Important: The comm port time-out on the Network B EGX must be greater than then comm port time-out on the Network A EGX. For example if the EGX on Network A has a time-out of 5 seconds. The time-out for the EGX on Network B should be about 2 seconds greater.

Both PC' can access information from each CM or PM by using Modbus TCP/IP protocol to their respective EGX.
Both PC's will use the same device addresses when making requests for data from each meter.

Additional Information: The COM2 on the EGX200 port does not need to have any devices listed in its device list.

The EGX100 could be substituted with a different protocol converter.




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