Substitution value mode

In certain cases, it is possible to transfer a substitute value instead of the true process variable value. The substitute value modeparameter describes where and in which cases the substitute value is transferred instead of the true process variable value.

The settings jointly describe the transfer time and the transfer target for the replacement value.

	Setting	Description of the
Transfer time	Send on startup	The replacement value is written when the variable server is started. This can be used to initialise a process variable.
	Send if communication is interrupted	The replacement value is written to the process variable in the variable server in the event of a communication error. The transfer to the communication component has no function here, as the process variable in the communication component cannot be written to in the event of a communication error.
	Send on exit	The substitute value is written to the PLC via the communication component when the variable server is terminated. This can be used as a message to the PLC that all visualisation applications have been terminated. The replacement value is not transferred to the process variable in the variable server, as this has just been terminated.
Transfer target	Enter in variable	The replacement value is written to the process variable in the variable server at the time of transfer. Application controls display the replacement value in this case.
	Send to the communication component	The substitute value is written to the communication component (OPC server/driver) at the specified transmission time.

Parameters for module: