Unity3D Android application, work with PLC

Can I create an android application which will work with PLC device on USB ?

Interested in exchange with the PLC.

If you mean programmable logic controller, then yes. USB is probably the hardest route to go though, most PLCs communicate over a specific field-bus. Best one hands down would be a Beckhoff controller. They have an ADS layer for EtherCAT machine control communication with C# libraries.