Introduction
The ACL-8454 is a general purpose timer/counter and digital I/O card for IBM PC/AT or compatibles. It uses the popular 82C54 timer/counter chip for event counting, pulse measurement, frequency measurement and pulse generation. In addition, this card supports 8 digital outputs and up to 16 digital inputs.
The ACL-8454 has two 84C54 chips on board and up to four chips can be supported. It provides at least six or at the most twelve 16-bit down counters. Each counter can be configured as different clock sources and gate controls by changing the jumper settings. In addition, you can cascade two 16-bit counters for timer pacer interrupt source.
AT interrupts (IRQ3~IRQ15) are supported by the ACL-8454, and both internal and
external interrupt sources are jumper selectable. Up to two sets of timer pacers can be
generated by two cascaded 16-bit counters, which can be used as an internal interrupt source.
Features
The ACL-8454 is supported by a set of drivers and examples, the standard software includes the following:
Windows DLL Driver
A high performance Windows 3.x DLL driver for
timer/counter functions is supported. The users can use this driver to
program their own Windows timer/counter applications.
The 8254 Programmable Interval Timer
| Programmable Counter | |
| Type of counter | Intel 8254 or equivalent |
| Counter mode | Down (binary or BCD) |
| Maximum input frequency | 8MHz |
| CLK period | 125ns min. |
| Counters | 6 independent 16-bit, up to 12 available |
| Input low voltage | -0.5V min., 0.8V max. |
| Input high voltage | 2.0V min., Vcc+0.5V max. |
| Output low voltage | 0.45V max. |
| Output high voltage | 2.4V max. |
| Base frequency | 4MHz |
| Frequency stability | ±100PPM |
| General Specifications | |
| Bus | PC/AT |
| Slot | One 36-pin and one 62-pin |
| Connector | 37-pin D-type female |
| I/O port address | Hex 200~hex 3F0 (8 bytes) |
| Interrupt level | IRQ3~IRQ15 |
| Operating temperature | 0°~50°C |
| Storage temperature | -20°~80°C |
| Humidity | 0~90%, non-condensing |
| Power consumption | +5V @ 600mA typical, 1A max. |
| Digital Output | |
| Output channels | 8 |
| Input logic low voltage | 0.5V max. @ 24mA |
| (Sink) | 0.4V max. @ 12mA |
| Input logic high voltage | 2.0V min. @ 15mA |
| (Source) | 2.4V min. @ 3mA |
| Driving Capacity | All inputs and outputs are TTL/DTL compatible and outputs will drive 1 standard TTL load (74 series) or 4 LSTTL (74LS) loads |
| Digital Input | |
| Input channels | 8, up to 16 available |
| Input logic low voltage | -0.5V min., 0.8V max. |
| Input logic high voltage | 2.0V min., 5.0V max. |
| Input loading current | 0.2mA max. @ 0.4V |
| Input hysteresis | 0.4V typical, 0.2V min. |
| Cat No. | Product Description | Price |
| ACL-8454/6 | 6-Channel Counter/Timer Card | $149.00 |
| ACL-8454/12 | 12-Channel Counter/Timer Card | 169.00 |
| ACLD-9137 | Direct Screw Terminal Board | 42.00 |
| ACLS-DLL3 | Windows DLL Driver for ACL-8454 | 59.00 |
©1995 Circuit Specialists, Inc.