SCADA and HMI Graphics... Why Bother?
Thursday, September 20, 2018
Here we are in 2018 and still process plant operators, maintainers, owners, and even the PLC & SCADA people who put the operator interfaces together argue... Green = running, Red = Running... and on it goes. Nobody can agree.
There's an ISA Standard (ISA101) which deals with the whole lifecycle of control systems but the one thing that has come out of all of this is that our HMI & SCADA Graphics standards have for years been... well, rubbish. One of the key goals of ISA101 is to deliver a system that results in safer, more effective, and more efficient control of a process, under all operating conditions and which will improve the user’s abilities to detect, diagnose, and properly respond to abnormal situations... doesn't sound too hard does it?
One of the outcomes of the whole process is graphics standards which on the surface look boring and disinteresting (can you say greyscale?)... and that's the whole point up until there's a problem in the process. That's when the correct use of colour makes a difference with studies showing that operators are less likely to miss a problem with a well thought out greyscale HMI as opposed to the traditional HMI which looked like a mad piece of modern art.
Operators do 'miss stuff' when they're busy or just plain fatigued.. A quick story... about 18 years ago a process plant bogged their tailings thickener on nightshift... 23:45pm to be exact. If you don't know processing, bogging a tails thickener is a big deal. The operators blamed the SCADA and the PLC techs and 'the system' which gave no warnings (it did), and swore that the tails thickener page was always displayed and they always watched it. To prove a point the PLC techs put a shark (we'll call him Bruce) in the thickener... Bruce did laps from 23:00 to midnight and then disappeared. It took 3 months for the control room operators to notice Bruce so I guess you could say that the operators weren't doing what they said they did (watching the thickener at all times). In reality, they shouldn't have to sit with their eyes glued to something, - if there's a problem it should stick out like a sore thumb, and that is what the whole ISA101 / greyscale thing is about...
Mine Site Recommissioning
Wednesday, August 01, 2018
This last week we've looked at another processing plant for a client with a view to recommissioning.. it's an old one and it has had more than a few 're-starts' over the years.
The interesting thing is that it's one where we've been many years ago and you can't help but look around at the changes.. The township, concentrator, power station, and most buildings are mostly all demolished and removed and the bush has taken over. The plant itself has been left to it's own devices for over a decade but despite that it's looking like a fair percentage of the hardware has survived due (mostly) to the low humidity of the location.
There's still plenty of work that will need doing in order to make things work again, but in this case Mother Nature has been kind. This isn't always the case and the best thing that any owner of a plant that's closing down can do is to prepare it properly for closure... chances are it's going to be re-started by someone one day or sold on, and the time and effort put in to a decent closure strategy will be repaid many times over. Here's a decent article on what needs doing: