Not with modbus, many years ago I did a simulation where I needed to simulate the communications from a PLC to/from a number of Nobel weighing units, this was pretty simple as the weigher just sent basic information & the commands were pretty simple i.e. weight read was 011346checksumCR
so address 01, weight 1346, checksum, carriage return. so it is reasonably simple, however, modbus can be tricky, first of all calculating the CRC checksum is not for the faint hearted, again the addressing models can be awkward i.e. bas of 0 or 1, i.e. do you address say 4000 as 4001, you certainly need to know the addressing model of the particular instrument.
attached is a typical message to read holding registers.
There are many hits on google about modbus & how you configure/decode the messages.
I have done Modbus RTU in pascal & VB is capable again this was a simulation of a sorter but at least I had the full spec on the sorter from the guy who wrote it.
CRC checksum is going to take you a bit of time again there have been a number of articles on how to do it.
Here:
https://en.wikipedia.org/wiki/Cyclic_redundancy_check
A typical read holding registers
