IPC+ soft logic

More than ten years ago, several experts in the United States and Europe had a long debate on this issue. One question revolved around how to realize IPC+ soft logic was reasonable, because there were mainly several voices at that time. One was completely opposed to the use of IPC in control, because of the obvious reliability problem, and how to pay equal attention to the compatibility and reliability of the operating system. The other is to fully support the application of IPC in industrial control, and think that the standard PC software and hardware should be completely used, so that the advantages of compatibility and openness can be fully reflected. The last one is a compromise scheme, in which PLC is inserted into IPC as a board of IPC. There are also several schemes in the implementation:

Scheme 1: standard operating system, including WINNT (including XP, 2000, NT, etc.), linux, DOS, plus soft logic software.

Scheme 2: add PLC card to the standard operating system, so that the control will not be affected when the computer crashes, and the PLC will not be affected when the computer is restarted. At the same time, the data interaction between PLC and PC is carried out through shared memory or dual-port RAM. So that it can have the openness of PC and all kinds of resources, and at the same time ensure the reliability of the control part.

Scheme 3: the redesigned hardware system, such as modular structure and soft logic software, makes its hard reliability exactly the same as that of PLC.

From the above scheme, there are some markets in some special applications, mainly in transportation control, image and display. Option 2 is a very conservative approach, but the cost is relatively high; Scheme 3 is actually a PLC.