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© Sealevel Systems, Inc.
SeaI/OUSBSERIAL | SL9177 04/2022
Introduction
SeaI/O™ USB serial expansion modules provide an easy way to add RS
-232 or RS485 serial ports to a Relio
industrial computer, SeaPAC touchscreen computer, stack of SeaI/O modules, or anywhere serial devices need
to be connected via an available USB port.
Available in four and eight port models, the serial ports appear as standard COM ports to the host system
enabling compatibility with legacy software. SeaI/O USB serial modules support data rates to 921.6K bps and
are designed with a statemachine architecture that greatly reduces the host CPU overhead when communicating
over multiple ports simultaneously. Status LEDs integrated into the RJ45 connectors display transmit and
receive data activity.
With the unique VersaCom multi-interface connector design, both RS-232 and two-wire RS-485 signals are
always present and active on the RJ45 serial connectors. Simply select the appropriate pin out for RS-232 or
two-wire RS-485 on each individual port. There are no internal jumpers or switches to set, so field installation
and service is easy.
The USB serial modules are powered from your 9-30VDC source or your choice from several Sealevel power
supply options. For conveniently powering serial peripherals, the supplied power is fused and connected to pin
5 on each of the RJ45 serial connectors. A high-retention USB type "B" connector helps to prevent accidental
disconnection of the USB cable.
An RS-485 pass-through connector on the side of the SeaI/O USB serial modules provides additional I/O
capabilities using SeaI/O "N" series expansion modules. Up to 246 additional SeaI/O expansion modules can be
added and are available with Reed and Form C relays, optically isolated inputs, TTL interfaces, A/D and D/A
functionality.
This manual covers the installation and operation of these SeaI/O products:
USB Serial Expansion Modules
SeaI/O-641U
–
4-Port RS-232 RJ45 Serial Interface
SeaI/O-647U
–
4-Port RS-232, RS-485 RJ45 VersaCom Serial Interface
SeaI/O-681U
–
8-Port RS-232 RJ45 Serial Interface
SeaI/O-687U
–
8-Port RS-232, RS-485 RJ45 VersaCom Serial Interface
