I am going to be integrating an AB SLC 5/05 in to our current system and I have a few concerns about the interdependence of the PLC logic and the remote operation I want Ignition to take care of.
I think the easiest way to describe my question is through an example.
Let’s say I have an analog value for a VFD tied into the RSLogix500 code and that value is automatically controlled by the PLC logic. However, I would also like the ability to override that analog value remotely through an Ignition client. In this case I would have an analog output from the PLC that is accepted as an input by the VFD to control its speed. I would want to be able to override that PLC output remotely through an Ignition client. I assume that when the RSlogix500 code is wriiten I will need to include the ability for an input from Ignition to override the value determined automatically by the PLC logic.
If that is not the case then will I just make the analog tag read/writeable in Ignition and there is no need for the RSLogix500 code to be aware that a seperate analog input has the ability to override the tag?
Perhaps both options are possible and I am overthinking this. What I am trying to avoid is the need to go in and modify the RSLogix500 code in order to have some remote functionality through Ignition. If I can set it up initially in a manner that will allow me to only code the PLC one time I can save myself a lot of trouble.
Any input helps. Thanks
