ISP Value in Communication Variable (for Userdefined Data Types).
In AC800M Controller, When using a userdefind datatype as communication variable how can we give the ISP Value.
If the direction of a communication variable is out, the application that holds this
variable is the Server application. If the direction of a communication variable is in,
the application that holds this variable is the Client application.
An In variable is resolved if there exists a corresponding Out variable with the same
name in the control network.
The data type of the communication variable can be a simple type or a structured
For communication variables with structured data types, bidirectional
communication is also possible if the reverse attribute is set. As the effect of reverse
attribute, some of the components communicate in forward direction while others
communicate in backward direction. For this type of communication, only one
server and one client can be connected (1:1).
The ISP (Input Set as Predefined) value of the In communication variable is also
entered while defining the In communication variable. This value is assigned for the
communication variable if there is an error in communication. If the ISP value is not
entered, the last good value is assigned if there is an error in communication.
For structured data types, the ISP values can only be set in the data type for each individual component. Hence, it is not possible to configure instance specific ISP values for structured data types.
More details on 3BSE035982-510_-_en_AC_800M_5.1_Communication_Protocols.pdf