AIO8
8-Input A/D Converter and Counter/Timer Card
FEATURES
- Eight
A/D channels, 12-bit resolution
- Programmable
scan rate
- Foreground/background
operation
- Seven
bits digital I/O
- Three
16-bit programmable counter/timers
- Can
assert interrupts
- Event,
period, pulse, and pulse-width counting
FUNCTIONAL
DESCRIPTION
AIO8
is an economical multifunction, moderate-speed, multiplexed
analog-to-digital converter card with digital I/O and with
counter/timers. It can be used with ISA-bus computers. The
card is 7" long and requires one slot in the computer.
All external connections are made through a standard 37-pin
D-type connector at the rear of the computer. PC bus power
(+5V, +12V, and -12V) is provided at the rear connector. This
allows additional user-designed interfaces for input signal
conditioning, expansion multiplexers, etc.
ANALOG
INPUTS
AIO8
accepts eight analog inputs. The full-scale input for all
analog channels is ±5V (0.00244V resolution). Inputs
are single-ended with a common ground and can withstand a
continuous overload of ±30V and brief transients of several
hundred volts. The A/D converter is a 12-bit successive-approximation
type with sample and hold input. Conversion time is typically
25 microseconds (35 microseconds max.) and, depending on the
software and the computer used, throughput rates up to 4,000
samples/second are attainable.
DISCRETE
DIGITAL I/O
Seven
bits of discrete digital I/O are provided; one 4-bit output
port and one 3-bit input port. Each output can drive five
standard TTL loads. The output port, if not used to select
analog input expansion channels, may be used for general purpose
applications.
INPUT
SYSTEM EXPANSION
The
card supports up to eight AIM-16 or LVDT-8 analog input expansion
cards (or mixtures). A 3-bit standard LSTTL logic output from
AIO8 is used to select any one of the LVDT inputs at an LVDT-8
and a 4-bit LSTTL logic output from AIO8 is used to select
one of 16 analog input channels at the AIM-16. The eight-input
analog multiplexer on the AIO8 card is software addressable
and an input expansion card can be connected to each input
for a maximum of 128 analog data channels in the system. To
accommodate more than 128 inputs, either a second AIO8 (and
companion input expansion cards) can be used or you may wish
to consider using the AD12-16.
COUNTER/TIMER
A
type 8254 counter/timer chip is included on the card. This
chip contains three separate 16-bit down counters. One of
the counters is connected to a submultiple of the system bus
clock and all I/O functions of the other two counters are
available to you at the I/O connector. The counters can be
used to generate periodic interrupt requests, for event counting,
pulse and waveform generation, frequency and period measurements,
etc. Timed A/D conversions may be initiated by the counter/timer
if a jumper is installed on the I/O connector. Also, software
provided by Chassis Plans includes means to use these counters to
provide programmable gain commands to the instrumentation
amplifier on board the AIM-16 expansion multiplexers.
INTERRUPTS
Interrupts
are supported from external inputs. Selection of input levels
IRQ2 through IRQ7 is made by jumper on the card. Interrupts
are software enabled and disabled. An interrupt request may
be canceled by either:
a)
Computer reset signal, or
b)
Writing a command word to the card; i.e., by either updating
the channel selection on the associated AIM-16 expansion
card or on the AIO8 multiplexer.
SPECIFICATIONS
Analog
Inputs
- A/D
Type: Successive approximation.
- Resolution:
12-bit binary. Coding is offset binary.
- Number
of Channels: 8 single-ended inputs w/common ground.
- Voltage
Range: ±5 VDC.
- Overvoltage
Protection: ±30 VDC.
- Input
Impedance: 10 Megohm or 100 nA at 25°C.
- Accuracy:
0.02% of reading ±1 LSB.
- Linearity:
±1 LSB.
- Temp.
Coefficients: ±10 µV/°C zero stability.
±25 µV/°C gain stability.
Digital
Inputs / Outputs
Inputs
- Logic
Low: 0 to 0.4V at 8 mA sink.
- Logic
High: 2.4 to 5.0V at 0.4 mA source.
Outputs
- Logic
Low: 0 to 0.4V at 8 mA sink.
- Logic
High: 2.4 to 5.0V at 0.4 mA source.
Counter/Timer
- No.
of Counters: Three 16-bit down counters. Clock input
to one is ½ the PC system clock frequency; clock
inputs to the others can come from external sources.
- Input
Voltage Levels:
Low: 0 to 0.8V.
High: 2.4 to 5.0V.
- Output
Voltage Levels:
Low: 0 to 0.45V at up to 2.0 mA sink.
- Clock
Period: 125 nSec min.
- Clock
Rise and Fall Time: 25 nSec max.
Environmental
- Operating
Temperature Range: 0° to 60°C.
- Storage
Temperature Range: -20° to +70°C.
- Humidity:
0 to 90% RH, non-condensing.
Regulatory
Compliance 
Declaration of Conformity, and Test Reports are on file.
Users must use appropriate shielded cables.
| Part
Number |
Price(USD)
|
| AIO8 |
195.00
|
View / Download Manual (in .PDF
format)
