User manual

IEC61131 User and Reference Manual
April 22, 2008
122
The Server selection selects whether the server is enabled. If this option is enabled the
controller supports incoming slave messages. Disabling this option prevents the controller
from processing slave messages. Master messaging is always enabled.
The Master Idle Timeout determines when connections to a slave controller are closed.
Setting this value to zero disables the timeout; the connection will be closed only when your
program closes it. Any other value sets the timeout in seconds. The connection will be
closed if no messages are sent in that time. This allows the slave device to free unused
connections. Valid timeout range is 0 to 4294967295 seconds. The default value is 10
seconds.
The Server Idle Timeout determines when connections from a remote device are closed.
Setting this value to zero disables the timeout; the connection will be closed only when the
remote device closes it. Any other value sets the timeout in seconds. The connection will be
closed if no messages are received in that time. This allows the controller to free unused
connections. Valid timeout range is 0 to 4294967295 seconds. The default value is 250
seconds.
The TCP Port sets the port used by the Modbus/TCP protocol. In almost all cases this
should be set to 502. This is the well-known port number for Modbus/TCP. Modbus/TCP
devices use 502 by default, and on many devices the value cannot be changed. It is
suggested that you change this value only if this port is used by another service on your
network. Valid port number range is 1 to 65534. Consult your network administrator to obtain
a port if you are not using the default.