VSE 003 Local port RS-485 interface module

Module VSE 003 provides:
a) Galvanically isolated RS-485 interface to External I/O modules
b) Galvanically isolated RS-485 interface for a "Service Bus"
c) The VSE 003 is attached to the LOCAL serial port at the back of a VAMP 200-series relay.

The RS-485 interface supports 2- wire connection. There is a dip switch to switch the termination resistors on or off. The direction control of the RS-485 transceiver is done automatically. The automatic direction control turns the transceiver to transmit mode after detecting the falling edge of a 0-bit. When the transceiver is changed to receive mode, the RS-485 line changes state to logic 1 state due to the biasing resistors.