Verification and usage rules for routines using a program parameter of another program
An instruction of a program can read from or write to the program parameters of other programs within the limitations listed here. If any condition is not met, the verification fails and the program cannot be downloaded to the controller.
Verification and usage rules for all program parameters
- Only Input, Output, or Public parameters can be used in the logic of other programs.
- An Output parameter cannot be written to by logic of another program.
- A Local tag that is an alias for an Output parameter of another program cannot be written to by logic.
- A constant tag or parameter cannot be written to by logic.
- A tag that is an alias for a constant tag or parameter cannot be written to by logic.
Verification and usage rules for Input parameters
- A single part (member, element, or bit) of a program's Input parameter can be written to by another program or have a connection. Conversely, a single part (member, element, or bit) of a programs Input parameter cannot be written to by another program and also have a connection.
- Logic cannot write to a tag that aliases another program’s Input parameter when the Input parameter has a connection.
- Multiple instructions of another program can write to an Input parameter only if the Input parameter does not have a connection.
- Logic cannot write to an InOut parameter that connects to another program’s Input parameter that has a connection.
Verification and usage rules for safety programs
- All rules listed above that apply to Standard programs apply to Safety programs.
- Instructions in Standard programs can read Inout, Output, or public parameters of Safety programs.
- Instructions in Standard programs cannot write to any program parameters of Safety programs.
- Instructions in Safety programs cannot read any program parameters of Standard programs.
- Instructions in Safety programs cannot write to any program parameters of Standard programs
For an illustration and explanation of Input parameter errors see below for
Illustration and explanation of verification and usage rules for Input parameters
.Verification errors when offline and online with the controller
- When offline with the controller, unverified instructions can be saved into a project file. However, the project cannot be downloaded until unverified errors are corrected.
- When online with the controller, online edits cannot be finalized until unverified errors are corrected.
When verifying tags, routines, or the controller, errors found for the parameters, connections, and logic are shown in the Errors window. Selecting a parameter or connection error in the Errors window opens the Program Properties dialog box Parameters tab with the parameter that has the error selected. Selecting an error for the logic opens the language editor. A project that contains errors will not be downloaded to the controller until all errors are fixed.
Provide Feedback