Modbus RTU communication driver

Good afternoon, please tell me how to configure Modbus RTU communication between PCs and remote access
supporting this protocol, PC with QNX Neutrino v6.5, USB-RS485 interface converter (S-500)
( … rs485.html)? This task requires writing a driver? If so, how to dо this?

This depends on the interface you intend to use.
If it is based on a standard USB/serial converter chip, QNX will be able to mount the interface without writing a driver. If the USB/serial converter chip is not recognised by QNX, you will have to write a driver for it.

You will then require a MODBUS compatible software. Either a commercial one, an open source one or a self made one.
More informations here :