Hi,
Most technical equipment has some form of machine accessible interface. 20 years ago it would be a text file format, currently it may be a JSON or XML format used by a web-service.
Bottom line: PB will in most cases be able to access such API using standard PB functionality: Reading from data files, calling external function or a web-service returning JSON, XML; or some proprietary data format.
In rare occasions the communication protocol is complex and requires technical details hard to write in PowerScript. In such case there is often a DLL file that you can call as external functions. If no such luck, you may need to write some kind of facade in C# or C++ and then call that facade from PowerScript.
I know of a product written in PowerBuilder that interfaces with pretty much any kind of standard equipment you find on an industrial manufacturing floor using files, external functions, web-services, or some other kind of standard interface that PowerBuilder supports.
HTH /Michael