Impulse 8018 - Manual (Page 9)

© Sealevel Systems, Inc.
- 7 - PIO-24.LPCI User Manual
Digital I/O Interface
The PIO-24.LPCI’s 24 digital I/O channels are accessed via two (2) 26-pin header
connectors. The included CA315 connects to the two 26-pin header connectors on
the PIO-24.LPCI and brings them out to a single 50-pin IDC connector, which is
compatible with industry-standard relay racks. The headers provide 24 bits of digital
I/O divided into three eight-bit ports. Each port may be individually configured via
software command as input or output.
26-pin Header Connectors
You will need to install the bracket assembly and cable to the PIO-24.LPCI prior to
installing it in the PC. The PIO-24.LPCI’s bracket features a unique cable clamp that
provides a solid strain relief to prevent inadvertent cable removal.
The 26-pin connectors have the following pin out:
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 PIO-
24.LPCI. 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.
Programming for Linux
SeaI/O for Linux consists of two major parts: a kernel module and a library. The
kernel module is a simple IO pass-through device, allowing the library to handle the
more sophisticated functions provided to SeaI/O users. It is provided in a ‘tarball’
format and can easily be compiled and included in the kernel build.
Direct Hardware Control
In systems where the users program has direct access to the hardware (DOS) the
tables that follow give the mapping and functions that the PIO-24.LPCI provides.