I currently have a minimal install of Red Hat 6.5 running, on the machine I need to talk to a modbus device. I am wondering what tools and drivers are needed on a linux machine to talk to a modbus device for the main purpose of reading?  I did see some on google and I'm interested if anyone has actual experience using different libraries?
talk to modbus device
linux;rhel;drivers;devices;serial port
You can use a programming language to open a socket and roll-your-own library, using the modbus spec.  Otherwise you can use an existing library, I have no experience with any of them, but this looked promising:  http://libmodbus.org/documentation/