Chapter 2: Functional Description
Manual Number: 00650-004-5
Page 2-1
Chapter 2: Functional Description
The ADIO1600 is a multifunction high-speed analog/digital I/O card for use in IBM Personal Com-
puters. It is a 3/4 length card that can be installed in an expansion slot of an IBM PC/XT/AT and
compatible computers. With this card installed, the computer can be used as a precision data
acquisition and control system or as a signal analysis instrument. The following paragraphs describe
functions provided by this card.
Analog Inputs
The card accepts up to eight differential or 16 single-ended analog input channels. Inputs are
protected against overvoltages (by the internal multiplexer diodes (rated at 20mA maximum) con-
nected to the + and - of the power supply. An external series 1K resistor is suggested if serious
overvoltage or static problems exist. As an alternative, a factory installed special multiplexer will
extend overvoltage protection further. The channel input configuration is jumper selectable on the
card providing a choice between sixteen single-ended channels or eight differential channels. In the
latter case, common mode rejection ratio is a minimum 80 dB and common mode voltage range is
±12V.
Inputs are amplified by an instrumentation amplifier with a combination of switch selectable gains of
1 or 2, and software selectable gains of 1000, 100, 10 and 1 to provide voltage ranges of ±0.005,
±0.01, ±0.05, ±0.1, ±0.5, ±1 , ±5 and ±10 volts bipolar and 0.01, 0.1, 1, and 10 volts unipolar (gain
switch must be set to x2).
The ADIO1600 uses an industry standard 12-bit successive-approximation analog-to-digital con-
verter (A/D) with a sample and hold amplifier input. Under the right conditions, max throughput is
100,000 conversions per second.
A/D conversions may be initiated in any one of three ways: (a) by software command, (b) by
on-board programmable timer, or (c) by direct external trigger. In turn, data may be transferred to
the computer by either of two software selectable methods: (a) by polling for end of BUSY or (b) by
end of BUSY interrupt.
Input System Expansion
The card can be used with up to 8 external AT16-P analog input expansion cards. The ADIO1600
does not support the programmable gain capability of the AT16-P and requires jumper changes on
the AT16-P to support manual gain. Each AT16-P card provides capability for 16 differential inputs
and, thus, there can be up to a maximum of 128 inputs per combination of AT16-Ps and ADIO1600.
The first AT16-P is connected to the ADIO1600 by a special cable adapter and ribbon cable, any
additional AT16-P cards are daisy-chained to each other by ribbon cables. Cabling information is
provided in Appendix B.