Wondering if it would be possible to use Scadamobile on older PLC’s (such as an Alan Bradley SLC503) via the serial port and a PC, transferring the data to a excel spreadsheet with RSLinx (using DDE or OPC) and then using that excel file as the source file for ScadaMobile.
I am not sure if I completely get your idea, but the way I understand it, what you want to do is not possible.
The excel spreadsheet that SM uses is a means to provide it a list of tags to display. This spreadsheet must meet a particular format for SM to understand and make a proper use of it. Then SM uses the information contained in that spreadsheet to establish communication with PLC and to display the requested PLC data. In all cases SM establishes direct connections with PLCs using the relevant protocol, such as Ethernet/IP. ScadaMobile does not currently support OPC.
Said that, I may be missing some fundamental aspect of what you describe, so I would appreciate if you could clarify the particular setup you are thinking of. Thank you very much.