Hi, I am trying to set up a system with LabVIEW and modbus RTU to do the following;
1. Tell aPLC to operate a motor until one of two sensors (call them a or b) is activated,
2. get three readings from a modbus digital loadcell converter at intervals of about 1 minute,
3. Bundle the readings and the status of the sensors as well as several other sensors from
the PLC and output them along with time and date to a csv file.
4. go to the start and repeat forever ( I want this thing to run for at least a year)
I will need to be able to interupt for maintenance.
It would be good to be able to take the data off the master (a laptop) for analysis without interupting the process. Also file size might eventually cause a problem.
It would be nice if an alert could be made if the difference between the average of readings associated with sensor "a" and "b" went over a constant, but I want to implement this as soon as possible so I should only include this option if it is relatively easy.
A few pointers as to the best way to set about this would be greatly appreciated. I dont have the DSC or RT platforms only the latest modbus library and library from Plasmionique inc.
The PLC is a Barth STG680 MODbus which has its own graphical programming language so I will have to do those processes separately and report the status to registers for reading by the LabVIEW master.
The LabVIEW modbus examples I have seen mostly have a VISA function, I dont think my server devices will be compatible with VISA and I dont really understand what the start and termination blocks represent/what VISA is for?
Any answers greatly appreciated
Ed