How can I integrate a Sealevel SeaI/O or SeaDAC device with a third party application or PLC?

  Sealevel SeaI/O and SeaDAC devices are fully compatible with other Modbus compliant devices, PLCs and applications.  Many third party software applications and PLCs support interfacing digital I/O devices via the Modbus protocol. Sealevel devices with USB, RS-232, or RS-485 interfaces use the Modbus RTU protocol.  Sealevel devices with Ethernet or Wireless interfaces use the […]

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How can I sense or switch 120V AC from a PC?

  Sealevel offers Digital I/O TTL products that interface to industry standard relay racks and solid state relay modules that are designed to sense and switch AC voltages. Relay racks with solid state relay modules are also ideal for switching other relays and inductive loads.

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How do I compile SeaMAX example applications?

  For guidance covering the initial steps of compiling and running individual example projects using Microsoft Visual Studio, please refer to the SeaMAX API Documentation. To access the documentation from the Start Menu, click All Programs and locate the Sealevel Systems folder. In the SeaMAX subfolder, click on Documentation, and then click on the SeaMAX […]

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How do I interpret error return values from SeaMAX functions when debugging my SeaMAX program?

The SeaMAX API Documentation is the go-to source for understanding the error return values of a SeaMAX function. The SeaMAX documentation for each function provides insight into what the SeaMAX function encountered. In addition to the error code directly returned by the function, SeaMAX stores information about the last error that its functions encountered.  This […]

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How should I connect an optically isolated input and voltage supply to a dry contact output?

  Sealevel’s SeaI/O modules are a good choice for this application. For example, using a SeaI/O-430 module with 32 isolated inputs, we can connect the dry contact output to an optically isolated input in the following way: Connect output terminal A to the voltage supply’s “-” terminal. Connect output terminal B to the SeaI/O module’s […]

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What could cause an error from my first SeaMAX I/O function call?

  An error can occur in the first SeaMAX I/O function call if a SeaMAX function call that is necessary to set up the communication with the I/O device is either missing earlier in the code or it did not complete successfully. If the first I/O function call causes an error, verify either SM_Open() or […]

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What does Non-Polarized refer to on Optically Isolated inputs?

  Non-polarized means that the input trigger condition measures the voltage magnitude across the input, or alternatively the current magnitude through the input, regardless of the actual direction of the voltage polarity or current direction. This distinguishes these optically isolated inputs from polarized inputs because the optical isolator uses a back-to-back arrangement of light emitting […]

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What is “Flyback Voltage” and what should I do about it?

  A “Flyback Voltage Spike” occurs when the supply current to an inductive load such as a solenoid is interrupted. Any switching circuit for highly inductive loads should have flyback voltage protection to limit the voltage rise from the discharging coil and damage to the relay contacts. Flyback voltage protection limits the voltage rise when […]

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What is a Quadrature Counter and how is it used?

  A Quadrature counter, also known as a Quadrature decoder, shaft decoder, or rotary decoder, is a type of digital input that uses a two-bit Gray code input to increase or decrease a value. The Quadrature counter works in combination with an optical or mechanical encoder, also known as a rotary or shaft encoder, to […]

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