The ModBus option module has been specifically designed for use with the DHC-100 Positioner via plug and socket installation. This module provides an isolated RS-485 bus connection using the ModBus protocol. The on-board screw terminal strip provides easy connection to the bus (Terminals A, B, & Common). With an input impedance of 96K ohms, up to 256 units can be connected on the bus. On-board dip switches alow configuring the module for various bus settings: mode, baud rate, parity, node address, and line terminating resistor.