plcengineer123
Member
Hi,
I've been asked to display the pump efficiency on our HMI system (iFIX). They have requested a kind of bar graph to indicate if it's running near it's "Best efficiency point" or into cavitation zones. But they don't want the actual curve on the screen, just a moving bar as per ISA 101 HMI standards. The HMI part is easy, but I don't know how to calculate the actual value for efficiency.
I'd like to do it in our M340 PLC. We have the flow measurement of the pump and the VFD speed and the downstream pressure. I feel like it would be easy in Excel to do a VLOOKUP against a table of the curve values, but in a PLC? And it's a VFD so it's kind of a 3D lookup. I haven't been given the pump curve information yet so I'm not sure how many data points I'll actually have to work with.
I'm guessing I'll need some kind of arrays, but I've never worked with those much before. Any tips?
Thanks
I've been asked to display the pump efficiency on our HMI system (iFIX). They have requested a kind of bar graph to indicate if it's running near it's "Best efficiency point" or into cavitation zones. But they don't want the actual curve on the screen, just a moving bar as per ISA 101 HMI standards. The HMI part is easy, but I don't know how to calculate the actual value for efficiency.
I'd like to do it in our M340 PLC. We have the flow measurement of the pump and the VFD speed and the downstream pressure. I feel like it would be easy in Excel to do a VLOOKUP against a table of the curve values, but in a PLC? And it's a VFD so it's kind of a 3D lookup. I haven't been given the pump curve information yet so I'm not sure how many data points I'll actually have to work with.
I'm guessing I'll need some kind of arrays, but I've never worked with those much before. Any tips?
Thanks