I/O wiring connections are via 50-pin headers on the board. Two flat ribbon cables connect the board to
external devices. This provides compatibility with OPTO-22, Gordos, Potter & Brumfield, and all module
mounting racks. Every second conductor of the flat cables is grounded to minimize crosstalk between
signals. If needed for external circuits, +5 VDC power (resettable fuse) is available on pin 49 of each I/O
connector.
The board occupies sixteen bytes of I/O address space. The base address is selectable via jumpers
anywhere within the range of 000-3F0 hex. An illustrated setup program is provided with the board.
Interactive displays show locations and settings of jumpers to select the board address, interrupt levels,
and interrupt enables. Also, samples in several programming languages are presented in the Software
section of this manual and on the accompanying CD.
The board optionally has an 82C54 Counter/Timer chip. This can be used for frequency measurement,
frequency output, pulse width modulation, pulse width measurement, event count, etc.
SPECIAL NOTE FOR PROGRAMMERS:
The one language
not
recommended for programming interrupt service routines is any version of
Visual BASIC. The recommended programming languages for IRQ based applications are Delphi, C++
Builder, or Visual C.
Specification
Digital Inputs (TTL Compatible)
•
Logic High:
2.0 to 5.0 VDC.
•
Logic Low:
-0.5 to +0.8 VDC.
•
Input Load (Hi):
20 uA.
•
Input Load (Lo):
-200 uA.
Digital Outputs
•
Logic High:
2.5 VDC min., source 32 mA.
•
Logic Low:
0.5 VDC max., sink 64 mA.
•
Power Output:
+5 VDC from computer bus (ext. 0.5A fast-blow fuse is recommended).
•
Power Required:
+5 VDC at 50 mA typical (all outputs HIGH, depends on features installed)
Optional Counter/Timers
•
Type:
82C54 programmable interval counters
• Output
Drive:
8mA.
•
Input Gate:
TTL/CMOS compatible.
•
Clock Output:
1MHz crystal-controlled oscillator.
•
Active Count Edge:
Negative edge.
•
Timer Range:
16 bits event counter, 32 bits rate generator.
Manual 104-DIO-48E, 24E
6
