Changing the Class of an Add-On Instruction

You can change the class of a safety Add-On Instruction so that it can be used in a standard task or standard controller. You can change the class in a safety project if the instruction does not have an instruction signature, you are offline, the application does not have a safety task signature, and is not safety-locked.

You can also change the class from standard to safety so that the Add-On Instruction can be used in the safety task.

Changing the class of an Add-On Instruction results in the same class change being applied to the routines, parameters, and local tags of the Add-On Instruction. The change does not affect nested Add-On Instructions or existing instances of the Add-On Instruction.

If any parameters or tags become unverified due to the change of class, they are identified on the Parameters and Local Tags tabs of the Add-On Instruction Editor.

If any of the restrictions for safety Add-On Instructions are violated by changing the class from standard to safety, one of the following errors is displayed and the change does not succeed:

· Routines must be of Ladder Diagram type.
· Safety Add-On Instructions do not support the Postscan routine.
· One or more parameters or local tags have an invalid data type for a safety Add-On Instruction.

You must edit the parameter, tag, or routine types before the class change can be made.