The CIO-COM485 model has been discontinued. Please contact our DAS Engineering department for possible alternatives.
The CIO-COM485 adds a single EIA compliant RS-485 port to your computer. RS-485 ports support longer transmission lines than the more common RS-232 and have the ability to switch between transmit and receive signals at the connector. The CIO-COM485 serial interface is designed around the standard serial communications chip used in PC serial I/O ports: COM1 and COM2.
The CIO-COM485 may be set up as COM1 or COM2 by
choosing the appropriate base I/O address and interrupt.
The register which controls transceiver enable/disable
is located at the board’s Base+7 address. Writing to
Base+7 controls the transmitters while reading from the
register reads the current status.
The CIO-COM485 is equipped with two DB9 connectors
for RS485 9 pin connectors and cables.
In addition, in compliance with RS485, pins 5 & 9 are
tied together as are pins 4 and 8.