Impulse 8207 User Manual - Manual (Page 7)

© Sealevel Systems, Inc. - 5 - SEALINK ISO-16 User Manual
Programming the SEALINK ISO-16
Sealevel’s SeaI/O software is provided to assist in the development of reliable
applications for the Sealevel Systems family of digital I/O adapters. Included on the
SeaI/O CD are driver functions for use in accessing the I/O as well as helpful
samples and utilities.
Programming for Windows
The SeaI/O API (Application Programmer Interface) provides a variety of useful
high-level function calls implemented in a Windows dynamic link library (DLL).
The API is defined in the help file (Start/Programs/SeaIO/SeaIO Help) under
“Application Programmers Interface”. This help file also includes detailed
information dealing with installation / removal of the software and information
about latency, logic states, and device configuration.
For C language programmers we recommend using the API to access the SEALINK
ISO-16. If you are programming in Visual Basic, using the ActiveX control
included with SeaI/O is advised.
Samples and Utilities
A variety of sample programs and utilities (both executable and source code) are
included with SeaI/O. Further documentation on these samples can be found by
selecting “Start/Programs/SeaIO/Sample Application Description”. Information
about where the files are physically stored on your disk is also included in this same
file.
Digital I/O Interface
The SeaLINK ISO-16 provides two parallel input/output (I/O) ports. The ports are
organized as ports A and B. The SeaLINK ISO-16 is a line-powered device
requiring a USB port capable of sourcing 500 mA.
Serial String
Each device has an eight digit alphanumeric serial string stored in non-volatile
memory. On the Windows platforms, this number is used to give each unit a
separate identity. This identity allows the device to be moved to any USB port or
hub port on your computer while retaining its device number. If a device becomes
damaged and is replaced the new device should be given the same serial string as the
device it is replacing. This string is stored in an EEPROM along with other critical
information. This EEPROM is read during enumeration. The device should not be
unplugged during its enumeration due to remote possibility that the data in the
EEPROM could be corrupted if power is removed during a read/write cycle to the
EEPROM. Enumeration is complete when the LED is lit.
The control panel utility provides the capability to read or modify this string.
However, setting the same string for two units connected to the same computer will
cause the second unit to fail enumeration, and make it invisible to the operating
system. Should this occur, unplug one unit and set the serial string for the other unit
to a different string.