User's Manual

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the mark as following:
3.4.2 Ethernet
The gateway has a 10/100Based-TXEthernet communication port (shown as Figure 2-3). The
connection is for access to gateway webpage and pass Modbus TCP HART-IP OPC and own
protocol communication.
For Ethernet connection, the user shall use Cat 5E type shield cable to connect Ethernet
concentrator, interchanger or router. The maximum length of cable is no more than 100m (328
inches).
3.3.3RS-485
The gateway assigns RS-485 (serial) connection (
Figure 3-7
) The user may assign the connection via
A and B serial Modbus terminals, and the connection can be used for communication between RS-
485 data bus and Modbus RTU.
The user may use 18 AWG single STP to connect gateway and RS-485 data bus. The bus length is
no more than 1220m (4000 inches). The user shall connect Tx+ (positive pole, sending) and
Terminal A, and connect Tx+ (negative pole, receiving) and Terminal B. The wiring shielded layer
shall be shut and insulated, to prevent gateway housing to contact terminals of other ends.
If 4-wire full duplex configuration is used for all the data bus, please change it into 2-wire half
duplex configuration, according to
Figure 3-8
.
Figure 3-8 Full Duplex to Half D Duplex
3.3.4 Power
The gateway is powered by 24 VDC (nominal value), and requires at least 500 mA current. The
positive and negative poles are connected to left side of terminal (
Figure 3-7
). The additional
housing ground wire is under the housing.
The user shall connect the power to the positive pole + of wiring terminal and negative pole of