Internal register mapping

[ashwani@912]

To avoid direct mapping from their internal registers to what we see on our supervisory control system they gave us access to a fixed address space like in the example diagram above. For example you create a list of all the commands you want our control system to access. Then in your own internal address space you allow access through local input and output buffers, which do the mapping. PLCs do this internal register mapping quite well, I’m not sure if this is possible with the CompacRIO.  Your suggestions will be Highly apreciated. I am developing a control 

software application for Laser Pump diode module using Compact RIO.

Sincerely 

A.P

[rolfk]

cRIO is not a PLC but rather a fully featured computer system. As such the software does whatever you program it to do, and nothing else! If you want to allow an external entity to communicate with your cRIO program, you have to implement this in some way and to do that you have to decide how you want to make that interface available to the outside world.

Possibilities are manifold:

- You could implement your own TCP/IP server that implements a specific protocol and that will define what data items you will allow to access.

- You could use shared variables that you either define (host) in your cRIO Realtime project or the host computer application. There are C interfaces to the NI Shared Variable Engine for Windows and other operating systems that you could call to allow non LabVIEW or LabWindows/CVI applications to access those variables.

- You could also use NI Network Streams.

- You could use one of the NI Industrial Protocol interface drivers to integrate your controller in an Ethernet/IP, EtherCAT or similar network.

- You could write your own serial port protocol that allows your controller to be connected to a serial port of another system.

Without one of these or a similar technology, the cRIO is simply happily sitting there and doing whatever you programmed it to do, without letting anyone peek or poke into its internal workings.