Sometimes it makes sense to leave OEM local controllers in place and communicate to them electronically. In this application a Case Controls 3PXBackBone controller can read all variables, change compressor set points, start, stop, load and unload the compressor by sending commands to the controller.
This is not a substitute for load sharing. The program in a microprocessor as a local controller cannot be modified to work in a true load sharing scheme.
Once all of the controller data is mapped into the 3PX system it is organized, documented and made available for third party PLC programs, Visualization, SCADA, and DCS systems.
Currently 3PX has predefined maps to read and write data to several OEM controllers of centrifugal and Rotary Screw compressors.