The IO connection is synchronous, by default.

The following global parameter can modify the default behavior of cyclic delays for unsolicited communication and allow you to indicate that an asynchronous connection is requested.

MBETH_ASYNC_CONNECTION

For	Project
Purpose	To switch between synchronous and asynchronous connections.
Value	Y
Default Value	N

<PORT>_ASYNC_CONNECTION

Where <PORT> is the number of the port.

For	Port
Purpose	To switch between synchronous and asynchronous connections on a single port.
Value	Y
Default Value	N

Important: There are Modbus TCP/IP bridges that do not provide a response as defined by the Modbus TCP/IP protocol when the queried device is not present. If such devices are configured on a CIMPLICITY port, use a synchronous connection on the port. Ports with devices utilizing such bridges are not supported in asynchronous mode.

More information

	Request Millisecond Timeout
	Unsolicited Communication.

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