December 2006 > Volume 5 Issue 12

Introducing SeaDAC Powerful USB I/O Solutions
Interfacing to real-world digital and analog I/O signals just became easier with the introduction of Sealevel's new SeaDAC USB Data Acquisition and Control modules. Choose from models offering optically isolated inputs, Reed and Form C relay outputs, A/D, and D/A functionality. SeaDAC I/O modules are perfect for a wide variety of applications including process control, facility management, security, and broadcast automation. Simply connect to any computer's USB port and use our robust software libraries to get up and running in record time.

SeaDAC modules are housed in rugged, attractive plastic enclosures and include a highly-retentive USB type B connector to prevent accidental disconnection. Power is supplied from the USB connection, so no external supply is necessary. Standard operating temperature range is 0°C to +70°C and extended temperature range (-40°C to +85°C) is optional.


  • Removable screw terminals simplify field wiring
  • High-retention USB type B connector prevents accidental disconnection of USB cable
  • Powered by USB connection
  • Easy to use software libraries and sample code included
  • Modbus RTU compatible
  • Attractive plastic enclosure
  • Backed by Sealevel's Lifetime Warranty

SeaDAC MIO-26 Multi-Function I/O Module
The first SeaDAC module released, the SeaDAC MIO-26 (Item# 8227), offers a powerful combination of I/O including 16 single-ended or eight differential 12-bit analog inputs, two 12-bit D/A outputs, eight optically isolated digital inputs, and eight open collector digital outputs. The module’s A/D inputs are independently software selectable for 0-5V, 0-10V, +/-5V, and +/-10V ranges and can be configured for measuring 0–20mA current loop. The A/D channels feature 5MHz bandwidth track/hold and 100ksps throughput. The module’s D/A channels are independently jumper selectable for 0-5V or 0-10V output range. Eight digital inputs are rated for 5-30VDC and provide 300V external isolation, while the SeaDAC MIO-26’s eight open collector outputs are ideal for switching 24V devices commonly found in industrial control applications.

For more information on the SeaDAC MIO-26, please visit the 8227 webpage.

SeaDAC PLC-16H High-Current Relay and Optically Isolated Input Module
The SeaDAC PLC-16H (Item# 8232) provides eight SPDT high-current Form C relays that can directly switch up to 6A loads at 250VAC and 100VDC. Additionally, eight non-polarized inputs can monitor 5-30VDC and provide optical isolation to protect the host computer and other sensitive equipment from voltage transients and ground loops that are common in industrial environments. For connecting I/O, removable terminal blocks are standard, enabling fast, versatile field wiring.

For more information on the SeaDAC PLC-16H, please visit the 8232 webpage.

Explore the entire family of SeaDAC I/O modules on our website!

In This Issue


Featured Accessory

Power Over Ethernet (POE) Kit with 5V/12V Switch
For new Power over Ethernet installations, the POE-SP-KT allows you to quickly and conveniently power your Sealevel SeaI/O Ethernet digital I/O module or Ethernet serial server.


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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Figure 1
An electromagnetic relay provides a movable contact (armature) that can switch between two contacts. An electromagnetic coil actuates the armature.

The Lowdown: Relay Basics
A relay contains a small electromagnet that controls an armature—a moving switch contact—held in a “normal” position by a spring. When energized, the electromagnet causes the armature to move to its other position. Remove the energy to the electromagnet and the spring quickly moves the armature back to its normal position (Figure 1). To learn more about relays, read Chapter 2 – Digital Outputs, part of the Digital I/O Handbook, on our website.

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