I am embarking on another project that requires Modbus communications and I was looking for some guidance on how best to handle some data.
The intention is to have the Arduino modbus slave return some static values used to verify flow calculations when polled by the master device under test. A poor-man's Multivariable Transmitter (MVT) if you will. I can build several small MVT simulators for much cheaper than I can purchase even 1 real MVT.
My question is around storage of the data. I need to store 96 registers of static test values (48 floating point values) so as not to run out of memory, and so the data can be read only. At first PROGMEM seems like the way to go, but it requires specific function calls to read and write the data. Is this even feasible with the SimpleModbus library?
The only way to update these test values should be via the source code itself as they are integral to proving the accuracy of a flow calculation.
As always, any assistance is greatly appreciated.