Modbus Poll Port Not Available =link=

: Only one application can access a COM port at a time. If another tool (like a PLC programming environment or another terminal) is already using the port, Modbus Poll will report it as unavailable.

Look at your taskbar. Are two or more Modbus Poll windows open? modbus poll port not available

If you work in industrial automation, building management, or SCADA integration, you have likely encountered a frustrating error message: : Only one application can access a COM port at a time