So, once you start with brand X it's for life? Upgrades, replacements, new equipment all go down road X?
I think that's what I'm trying to figure out; how do you decide it's time to change?
or, how do you help someone else see that?
No it isn't 'brand X' for life. My example is from a System Integrator viewpoint and caters to very large process systems, where the less time you spend on tedious PLC programming (IO mapping, device control logic, sequencing logic..etc) means either more time to focus on the process and what needs to happen, or it reduces the overall labor hours involved making you more cost competitive.
So investing into a brand platform, say ControlLogix and creating standard code and AOIs to handle the tedious stuff, and creating tools to generate the tedious logic are invaluable. You make an investment to become more efficient. Say 50% of the PLC logic required is all common stuff for all your projects, how you control a valve, motor, temperature PID, sequence logic. Well if 50% of the required PLC logic can be created in 10% of the time, that's good stuff. But you only get there by making the investment.
Moving to another platform means your existing code structures and philosophy may or may not work. You have to re-write some code, make variations and deviations, of course understand the core instruction sets as well. Then if you need to make automated tools to make development more efficient, its an undertaking. Of course keeping someone on-staff that understands it all is a challenge too.
Now, if your talking about small systems, less than 50 IO points, well 'brute-force' will probably prevail and you can get away with it on most any platform w/o much risk. But on large systems, that's a huge risk to change up the platform unless there is a very compelling reason to do so.
Paully, you changed to Ignition. How'd that happen?
Wondware continued to be a thorn in my side, costs to much, InTouch is dated, System Platform is bloated, and trying to interact with databases with scripting is just soooooooooo early 2000. FTVIew is about the same. The sales team sold a system which required a real in-depth recipe management system. A true batching solution was overkill and too expensive, CSV files where not practical. It needed to be database driven. While I've done custom database recipe management systems on InTouch prior, it simply wasn't good enough. Especially when it came to getting the recipe data to the PLC. Scripting that is not robust. This required almost 1000 different setpoints per recipe . Ignition with it's simple database connectivity, and transaction groups ensured robust results. It was also nice to work with Python for any scripting I required, really made things much easier than scripting in VBA or QuickScript.
