Tcp Connections - VSCOM ModGate Plus User Manual

6 Modbus Configuration
(a) with Direct Mapping
You can add, edit and delete TCP connections here. Like with serial ports the highlighting shows
whether a TCP Connection is used (green), unused (red) or a master (blue). Likewise the next to
last column called Devs shows the associated Modbus IDs when in DirectMappingMode; while the
LineMappingMode shows the Serial column with mapped Serial Port IDs in that place. Inbound
connections are shown with 0 as port number.
Unless you allowed unknown clients it is necessary to add a new connection for each Modbus/TCP
device you want to communicate with. Otherwise Modbus/TCP packets from unknown sources
are dropped. Please note that each entry needs a unique number called TCP Connection ID.
The IP/Host field can be either a numeric IP Address or a hostname. The Direction defines
who initiates the connection. Outbound is used when the ModGate Plus starts a connection;
likely for Modbus/TCP Slaves (Server). Inbound expects a connection to the ModGate Plus on its
ListenPort what a Modbus/TCP Master (Client) would do. The Port can be set for outbound
connections; otherwise it will show the TCP Port on which the ModGate Plus listens. There are
two types of ConnectMode available:
• Startup: establishes the TCP connection to the remote host when the Modbus gateway
application starts.
• Auto: does not connect to the remote host until the first packet for that destination shall be
delivered.
June 2018
Figure 20: TCP Connections
Figure 21: Edit TCP Connections
ModGate Plus User Manual
(b) with Line Mapping
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