User manual

IEC61131 User and Reference Manual
April 22, 2008
367
Notes
Translations may involve any combination of interfaces. The interfaces may be running a
Serial Modbus or Modbus IP protocol.
Slave Interface
Forwarding Interface
Serial Modbus Interface:
e.g. com1, com2, com3, or com4
Serial Modbus Interface:
e.g. com1, com2, com3, or com4
Modbus IP Interface:
e.g. Ethernet
Serial Modbus Interface:
e.g. com1, com2, com3, or com4
Serial Modbus Interface:
e.g. com1, com2, com3, or com4
Modbus IP Network:
e.g. Modbus/TCP, Modbus RTU over
UDP, or Modbus ASCII over UDP
Modbus IP Interface:
e.g. Ethernet
Modbus IP Network:
e.g. Modbus/TCP, Modbus RTU over
UDP, or Modbus ASCII over UDP
Modbus IP Interface as Forwarding Interface
When defining a translation to be forwarded on a Modbus IP network, the IP protocol must
be selected for forwarding interface. The IP Stack automatically determines which interface
to use by searching the network of the selected protocol for the destination IP address.
Also, when forwarding on a Modbus IP network, the forwarding destination IP address must
be entered as the ipFwd input. The ipFwd is entered as an IP address string of the format
255.255.255.255. The ipFwd is needed to know where to connect so that the command can
be forwarded to its final destination.
Modbus IP Interface as Slave Interface
Note that there is no input for an ipSlave. This input is irrelevant because we don‟t care
about the IP address of the remote master. We care only that the remote master connects to
the specified slave interface (ifSlave) and sends a command to be forwarded.
Serial Modbus Interface as Forwarding Interface
When defining a translation to be forwarded on a Serial Modbus interface, the forwarding
destination IP address can be left blank.
See Also
getsfip2, clearsf