Measurement Computing PC-CARD-D24/CTR3 - Manual (Page 7)

Chapter 1
Introducing the PC-CARD-D24/CTR3
Overview: PC-CARD-D24/CTR3 features
The PC-CARD-D24/CTR3 is a data acquisition and control board for IBM PC compatible computers with
PCMCIA/PC-CARD type slots. The primary functional elements consist of the following:
ƒ An 82C55 chip using TTL logic for 24 bi-directional digital I/O channels.
ƒ An 82C54 counter/timer chip that has three, 16-bit down-counters.
Under software control, the counters can be clocked internally from a 10 or 1 MHz crystal oscillator,
clocked externally, or chained to yield a 32- or 48-bit counter. Each counter can be gated (disabled) with
an external gate signal
The 24 digital I/O channels are divided into three ports — A, B, and C. Each port has eight I/O channels. At
power-on or reset, the digital lines are set as inputs. The board provides three independently programmable and
functioning 16-bit down-counters. You can access the clock input, gate, and output for each counter.
PC-CARD-D24/CTR3 block diagram
PC-CARD-D24/CTR3 functions are illustrated in the block diagram shown here.
Controller
FPGA
Attribute
Memory
Address Bus
Data Bus
1 MHz
Divide
by 10
10 MHz
10 MHz
Oscillator
Ho
s
t Bu
s
A
d
a
p
te
r
PC
M
C
IA
B
u
s Conne
c
tor P
1
(
6
8-
pi
n)
Digital I/O
Port
8-bits
Con
tr
o
l
Digital I/O
Port
8-bits
Digital I/O
Port
8-bits
Digital I/O
Port
8-bits
C
ontr
o
l
Digital I/O
Port
8-bits
Digital I/O
Port
8-bits
Digital I/O
Port
8-bits
Con
trol Digital I/O
Port
8-bits
Counter
1
Co
nt
ro
l
Counter
2
Counter
3
P
2 C
onn
ec
tor
(5
0-p
in
)
A0 (7:0)
B0 (7:0)
C0 (7:0)
CTR3 GATE
CTR3 CLK
CTR3 OUT
CTR2 GATE
CTR2 CLK
CTR2 OUT
CTR1 CLK
CTR1 OUT
CTR1 GATE
INT ENABLE
EXT INT
1 MHz OUT
Figure 1. PC-CARD-D24/CTR3 functional block diagram
Software features
For information on the features of InstaCal and the other software included with your PC-CARD-D24/CTR3,
refer to the Quick Start Guide that shipped with your device. The Quick Start Guide is also available in PDF at
. www.mccdaq.com/PDFmanuals/DAQ-Software-Quick-Start.pdf
Check www.mccdaq.com/download.htm for the latest software version.
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