Eaton Power Xpert PXM 4000, User And Installation Manual

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8 Setup on the Web Server Pages
CONFIGURING MODBUS COMMUNICATIONS
When Modbus/TCP is enabled, it can be configured to accept connections from either all clients
or trusted clients. You can set this by entering the IP address mask. The X.X.X.X setting ac-
cepts all connections; however, you can also use the mask to accept connections from any client
within a given subnet. For example, 192.168.X.X allows connections from any client in the subnet
192.168.0.0 to 192.168.254.254.
You can also use the meter as a gateway to a Modbus subnet and the Ethernet/LAN Setup page
provides settings for configuring the gateway. Either RS-485 serial port can be configured as the
connection to the subnet; however, there are some tuning considerations, which are covered later,
that may affect the choice of port. Either of the two RS-485 ports, or the RS-232 port, can be desig-
nated Master-Gateway and Master-IO. These can be designated as such on the Com 1 & 2 Setup
Edit page, and the Com 3 Setup page.
MODBUS TUNING
Modbus clients can respond differently to polling commands and may require additional time to
respond. Also, the meter may need to attempt to poll a device multiple times as it may be in a state
that does not allow it to immediately reply and therefore exceed the timeout value. You can use
these settings to configure your the meter to accommodate the various requirements of the devices
on the subnet.
If there will be a high level of polling traffic, you should seriously consider having the Display Link
on a separate RS485 port from the Modbus subnet. A high level of polling traffic can degrade