Use the Addressing Mode field on the SCADAPack tab to specify whether a SCADAPack controller uses Standard or Extended (Modbus) addressing.
Where a controller uses Standard addressing, Modbus addresses 1 to 255 are valid.
Where a controller uses Extended addressing, the valid address range is 1 to 65534. Use Extended addressing if more than 255 controllers exist on your system (see SCADAPack Controller Addressing).
Use the Address field to specify the controller address (see Specify the Controller Address in the Geo SCADA Expert Guide to the Advanced Modbus Driver).