February 2007 > Volume 6 Issue 2

Upgrade Embedded Systems with Bus-Independent I/O Expansion Boards

Sealevel’s SeaI/O-OEM family of bus-independent I/O boards offers a new choice for adding I/O to embedded systems. SeaI/O-OEM boards are perfect for expanding OEM computing platforms including EBX, EPIC, Mini-ITX, and ATX designs. For maximum flexibility, ordering options allow connection to a host computer via wireless Ethernet (802.11b/g), wired Ethernet, RS-485, USB, or RS-232. Multiple modules can be combined in a local stack or separated up to 4000 feet using the RS-485 Modbus RTU expansion interface.

Each SeaI/O-OEM board includes metal standoffs for easy mounting in any enclosure or cabinet. Designers can choose from fifteen I/O configurations offering Reed and Form C relays, optically isolated inputs, TTL interface to industry standard solid-state relay racks, A/D and D/A functionality, and RS-232/485 serial connectivity. Multiple units of any I/O type can be easily daisy chained together using convenient pass-through connectors.


  • Daisy chain up to 246 modules for powerful I/O network
  • Modbus RTU and TCP compatible
  • Field removable terminal blocks simplify field wiring
  • Status indicator LEDs for communication, power, and fault
  • Includes metal standoffs for versatile mounting options

Explore the entire family of SeaI/O-OEM bus independent I/O boards on our website!

Innovative SeaI/O USB Serial Adds RS-232/485 to Touchscreen/HMI Computers

Sealevel’s family of SeaI/O USB serial expansion modules easily adds up to eight RS-232 or RS-232/485 serial ports to a Relio R1000, SeaPAC industrial touchscreen computer, SeaI/O modules, or anywhere serial devices require a connection via USB.

With the unique VersaCom multi-interface connector design on RS-232/485 models, 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. Field installation and service is easy since there are no jumpers or switches to set.


  • Unique VersaCom connector allows RS-232 or two-wire RS-485 selection via cable pin out
  • Serial ports appear as standard COM ports to the host
  • Input power is fused and connected to pin 5 for conveniently powering serial peripherals
  • High-retention USB type “B” connector prevents disconnection of cable
  • Status LEDs display transmit and receive data activity
  • Data rates to 921.6K bps are supported
  • RS-485 pass-through connector provides additional I/O expansion using up to 246 SeaI/O "N" series expansion modules

Visit the SeaI/O USB serial expansion modules webpage for more information.

Protect Computers with Latest Optically Isolated 7-Port USB Hub

Once associated only with desktop peripherals, USB I/O devices are now commonly found in industrial and OEM applications. Voltage spikes, power surges, and ground loops that affect traditional serial interfaces also affect USB devices. Sealevel’s HUB7i is an optically isolated USB hub that connects up to seven USB peripherals and protects the host computer from voltages up to 5500 VAC.

The HUB7i includes an industrial grade wall-mount power supply that provides up to 4000 VAC isolation. For specialized applications, an optional medical grade power supply is available that increases the isolation to 5500 VAC, which offers the highest level of protection available from any USB hub manufacturer.

For more information, please visit the HUB7i webpage.

In This Issue


Featured Accessory

SeaPAC Flat Panel LCD Mounting Stands
Item# KT126
For prototyping and field installations, the KT126 LCD stands allow easy tabletop mounting of Sealevel SeaPAC flat panel computer systems. The LCD stands fit SeaPAC LCD displays from 6.4" to 17" and include a pair of brackets, rubber feet to prevent sliding due to vibration, and mounting screws to secure the LCD flat panel display.


Contact Us

Sealevel Systems, Inc
864.843.4343 tel
864.843.3067 fax

Mailing Address:
PO Box 830
Liberty, SC 29657

Shipping Address:
2779 Greenville Highway
Liberty, SC 29657

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Customer Spotlight

Heavy-Duty Spring Clamp Terminal Blocks Make Field Wiring Easy

Sealevel now offers optional spring clamp terminal blocks for SeaI/O modules and other devices with 3.5mm centerline spacing. The field-removable terminal blocks are keyed to prevent being inserted upside down plus the lever-style clamping mechanism provides superior wire holding properties by automatically adjusting the spring tension on wire diameters from 16-28 AWG.

Upgrade your SeaI/O modules with spring clamp terminal blocks using the ST-SP9-KT, which includes eight 5-position and one 6-position spring clamp terminal blocks. Spring clamp and screw terminal blocks are also available in packs of ten.

Discover the variety of terminal blocks available on our website.


Please call us today or visit our website at www.sealevel.com.