Evolution of SCADA Technologies - 1

C25 Remote Terminal Unit

There is nothing quite like working for a controls automation and engineering company for bringing high social-wc3-tech warriors down to earth. Probably uppermost in a controls product manager's mind is the support of long term useful plugged in technology. The automation that manages the control of plant and infrastructure is very static, and I have to say, totally anti-social.  Yes, believe it or not, social networking is NOT required to enable control systems to work.

The photo shows a single board Remote Terminal Unit, originally created in the 1980s using VME bus technology.  This was called the C25.  Although the C25 is now classed as obsolete, there are still many of these in operation on critical infrastructure throughout the world.  These days we replace these older remotes with the newer modular Foxboro RTU technologies.  The fit is close.. but not exact.  Features of the older technology which tend to change are the:-

• Wiring connectors - Older terminations
• Communications - instead of using Bell 202 we might use TCP/IP
• Protocol - instead of using Conitel - we might use DNP3
• User Programs - now here is the real challenge - these were generally built in older languages - early derivatives of BASIC or C programming - these days we might transition these to SALL programming with it's more protected logic code. IEC 1131 standard programming might also be required. 

Many of the components on these boards are difficult to find.  Repairing them is a challenge.  We tend to create newer technologies which try to extend the role and function of the older technologies, with a minimal installation cost.  I decided to read the book by Kevin Kelley - "What Technology Wants".  I believe that there is something about the use of these technologies, which have to remain in place without moving, without disconnecting, and without modification for over 30 years, which has to be explained.  I will be doing more posts on this topic as I embark on my travels in the next month or so.