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The ADl200 and ADA1200 Advanced Indusrial Contol boards turn your IBM PC/XT/AT or compatible into
a high-speed, high-performance data acquisition and control system. Installed within a single expansion slot in the
computer, each 1200 series board features:
. 16 single-ended analog input channels,
. l2-bit,5 microsecond analog+o-digital converter with 125 kl{z throughput,
. 15, tl0, or 0 to +10 volt input range,
. Resistor configurable gain,
. Three conversion modes,
. DMA transfer,
. Trigger in and trigger out for external triggering or cascading boards,
. 16 TTL/CMOS 8255-based digital I/O lines which can be configured with pull-up or pull-down resisrors,
' Three l6-bit timer/counters (two cascaded for pacer clock),
. Two 12-bit digital-to-analog output channels with dedicated grounds (ADA1200 only),
. +5, +10, 0 to +5, or 0 to +10 volt analog output range (ADA1200 only),
. Turtro Pascal, Turbo C, and BASIC source code; diagnostics program.
The following paragraphs briefly describe the major functions of the board. A more detailed discussion of board
functions is included in Chapter 3, Hardware Operation,and Chapter 4 , Board Operation and Programming.Tlte
board setup is described in Chapter l, Board Settings.
Analog-to-Di gital Conversion
The analog-to-digital (AlD) circuitry receives up to 16 single-ended analog inputs and converts these inpus
into l2-bit digital data words which can tien be read and/or transferred to pc memory.
The analog input voltage range is jumper-selectable for bipolar ranges of -5 to +5 volts or -10 to +10 volts, or a
unipolar range of 0 to + l0 volts. The board is factory set for -5 to +5 volts. Overvoltage protection to +35 volts is
provided at the inputs. The high-perforrnance A,/D converter supports resistor configurable gain circuiry so that you
can customize the input gain.
A,/D conversions are performed in 5 microseconds, and the maximum throughput rate is 125 kllz. Conversions
are controlled through software, by an on-board pacer clock, or by an external trigger brought onto the board
through the I/O connector.
The converted data can be Eansferred through ttre PC data bus to PC memory in one of two ways: by using the
microprocessor or by using direct memory access @MA). The mode of transfer is software-selectable and the DMA
channel is chosen by jumper settings on the board. The PC data bus is used to read and/or transfer data o pC
memory. In the DMA transfer mode, you can make continuous transfers directly o PC memory wittrout going
through the processor.
Digital-to-Analog Conversion (ADA1200 Onty)
The digiral-to-analog (D/A) circuitry on the ADA1200 features two independent l2-bit analog output channels
with individually jumper-selectable oulput ranges of -5 to +5 volts, -10 to +10 volts, 0 to +5 volts, or 0 to +10 volts.
Data is programmed into the D/A converter and a conversion is automatically triggered for a channel through a
single write operation. Access ttrrough DMA is not available.
8254 Timer/Counter
An 8254 programmable interval timer contains three l6-bit, 8-MHz timer/counters to support a wide range of
timing and counting functions. Two of the timerrcounters are cascaded and can be used internally for the pacer
clock. The third is available for counting applications, or it can be cascaded to the other two timer/counters.
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