3
© Sealevel Systems, Inc.
7105-DB9 Manual | SL9053 9/2021
Introduction
Overview
The PCI bus 7105-DB9 is designed with a DB9 connector compatible with the AC24AT and AC422AT Opto-
22 ISA bus cards. This allows Optomux devices to be controlled from PCs that do not have an ISA bus
expansion slot available. The 7105-DB9 provides a single field selectable port configurable as RS-422/485
supporting asynchronous data rates up to 460.8K bps.
Choose the RS-422 mode for long distance device connections up to 4000ft. where noise immunity and
high data integrity are essential. Select RS-485 and capture data from multiple peripherals in a RS-485 multi-
drop network. Up to 31 RS-485 devices can be connected to each port to automate your data collection.
In RS-485 mode, our special auto-enable feature allows the RS-485 ports to be viewed by the operating
system as a COM: port. This allows the standard COM: driver to be utilized for RS-485 communications.
Our on-board hardware automatically handles the RS-485 driver enable.
