San Diego, Calif.Need more I/O in your PC/104-based embedded industrial design? Board maker ACCES I/O Products has a new PC/104 board, dubbed the Model 104-II32-4RO, that packs 32 fully optically-isolated digital inputs, with COS (change-of-state) interrupt generation.
In use, optically isolating the board's digital inputs from each other, and from the rest of your circuitry, can ensure error-free data transmission in noisy industrial environments. The COS detection is selectable on a per nibble basis.
All I/O connections are made via one 34-pin and one 50-pin right angle header (vertical headers are also available on special order). As an 8-bit PC/104 board (with 16-bit pass through connectors), it can be installed in any embedded system that supports PC/104 or PC/104+ modules.
The less-than-$300 Model 104-II32-4RO board lets you connect an assortment of devices, including sensors, switches, controllers, and powered circuits. The board's inputs can be driven by either DC sources of 3-V to 31-V (or higher, by special order), or AC sources at frequencies between 40-Hz and 10-kHz.
The board also includes four electromechanical relay outputs. The electromechanical relays provide more flexibility than FET or other types of solid-state outputs; many kinds of signals can be readily switched.
The relays are Form C types (NC, NO, C) SPDT types. Their contacts are rated at 24-V DC at 1-A and 115-V AC at 500-mA, with contact resistances of less than 100-milliohms.
As such, the 104-II32-4RO can be used in a variety of PC/104 applications such as embedded SCADA (supervisory control and data acquisition), industrial automation, process control, scientific apparatus, and embedded OEM applications.
Each input circuit also includes a jumper-selectable filter to accommodate AC inputs. That's also useful for slow DC inputs in noisy environments. The filter can also be manually disabled to improve the board's typical response time to 10-us when used with faster DC inputs. The input impedance is 1.8-kohms.
To prevent erroneous input state change detections and interrupts, Schmitt triggers are used to ensure reliable logic to the host interface. A useful feature is a fused 5-V general-purpose output at a connector. The fuse is also resettable.
Finally, all interrupts are software controlled, letting the board generate an interrupt whenever one or more of the isolated digital inputs changes state. When an interrupt is received, an ISR (interrupt service routine) handles the request, polls the card once to read the state change, then clears the interrupt, enabling the board to detect the next change without processor intervention. IRQ sharing with other system devices is enabled for ease of system development and installation.
Operating System Versatility
The 104-II32-4RO plug-in board is supported for use in most operating systems, and ACCES I/O includes a free DOS, Linux and Windows package. The system will work in Windows 95, Windows 98, Windows Me, Windows NT, Windows 2000, Windows XP, and Windows 2003 systems.
The software support package also contains sample programs and source code in C for DOS, as well as VisualBASIC, Delphi, C++ Builder, and Visual C++ for Windows. Also incorporated is a graphical setup program in Windows.
Third party support includes a Windows-standard .dll interface that's usable from the most popular application programs. Embedded operating system support includes Windows XPe and Windows CE. Linux support consists of installation files and basic samples for programming from user level via an open-source kernel driver.
The 104-II32-4RO plug-in board is also available with options such as an economy version (no-COS), extended (industrial) temperature range operation, higher input ranges, no relays, and more.
Click here to view an engineering datasheet (in Adobe Acrobat .PDF format) on ACCES’s Web site.
For more details contact regional sales managers Marty Wingett or Marc Kryjewski at ACCES I/O Products, Inc., 10623 Roselle Street, San Diego, Calif. 92121. Phone: 858-550-9559. Fax: 858-550-7322. E-mail: firstname.lastname@example.org or email@example.com
ACCES I/O Products, 858-550-9559, www.accesio.com