Our recent experience with some DCS with Ethernet switches and commercial Servers being a part of the Controller and data acquisition system was not good. The issues we face when compared to earlier 'proprietary" systems are:

1. The wiring and layout does not give the reliability or ruggedness that was available earlier. The connections in the 20 port switch are so crowded that it is almost impossible to remove any one, if a requirement comes.

2. Is it not the DCS vendors responsibility limited for these third party "Commercial, off the shelf components" since they do not have any control on these manufactures.

3. Many a times due to obsolescence of the Server Operating System, the vendor expresses his inability to support the existing system. The customer is forced to buy the new OS and the application software suitable for the new OS. Since the old server does not support the new OS, we have to buy new server also. Since this is part of a very critical process control system, we have to get it from the DCS vendor to have an overall responsibility, at a price determined by him.

4. To make any change in the configuration the engineering activities that were being done in an easy, well documented and systematic manner earlier has become too software intensive and changes had to done in number of files for a single modification

5. Using commercially available hardware & software may be bringing some cost advantage. But to the end user the total life cycle cost is not reduced. Also whatever initial cost advantage is at the cost of reliability, robustness and ease of operation.

What is the industry view on these third party servers being a part of controller and data acquisition system? when used for very critical process control application.

If it is in the HMI / engineering station, it may be acceptable.

 

The real problem seems to be the design and business choices made by the DCS vendor. The older single source systems weren't necessarily all made by the DCS vendor either. The difference was that they stood behind and took responsibility for their design choices.

Your main complaints seem to centre around the third party software, especially the operating system. I am going to take a guess that the OS you are referring to is MS Windows, in which case the DCS vendor has absolutely zero ability to offer you any sort of long term support guarantees.

The root of the problem is that the software is still just as proprietary as before. It's just that the multiple third party proprietary vendors involved have no knowledge of or interest in the DCS market and have no incentive to put themselves out to support either you or the DCS vendor.

The answer would be for the vendor to incorporate open source solutions (OS, database, programming languages, etc.) to support their own DCS software, and to offer it to you *as* a package which they stood behind and maintained on an ongoing basis. That is a proven and successful business model in the IT industry, and there is no reason why it couldn't work in the DCS industry.