MODBUS RTU configuration on Linux based SBC

IoT Project for Elevator Management System.
Need a software developer a Python programmer to configure Single Board Computer (SBC).
Configure the SBC as follows:
1. Configure the READ function to collect the Data on RS-485 port from a Daisy Chained I/O modules.
Architecture diag. attached ( max. 8- I/O modules with 45 connection each, daisy chained and connected with SBC on RS-485 port)
2. Configure the Master - Slave and daisy chaining.
3. Configure the MODBUS registry.
4. Configure WRITE function to receive command from Cloud application and trigger the I/O board.
5. Push the data to third party cloud solution in JASON format.
6. Make sure the data is collected and pushed on the cloud software successfully.
7. Need assistance after deployment in case any ambiguity arises.
8. GUI for interactive configuration of the SBC. details will be shared to interested candidate on DM.

System details:
1. Single Board Computer ARM cortex A5, 500 MHz, with 64 MB RAM and 32 MB NAND flash
2. OS: YACTO-Linux Kernel 4.14.
3. Programming language: Python/ JAVA/ C++/ C

Looking for a Software developer having intense experience in RS-485 MODBUS configuration.
Successful completion can turn in to a long term association for up coming IoT projects.

Regards,
Upendra.