AIM-16
16-Channel Analog Multiplexer & Signal Conditioning
Card
FEATURES
- Supports
mixed Sensors: Thermocouples, RTDs, strain gages, voltage
and current inputs
- Multiplexes
16 differential inputs to one analog single-ended output
- Cold
junction compensation and break detect for thermocouple
inputs.
- Gain
programmable (0.5 to 1000) channel-by-channel
- Screw
terminals for input terminations on plug-in blocks
FUNCTIONAL
DESCRIPTION
Model
AIM-16 accepts, pre-amplifies, and multiplexes analog signals
for application to an analog-to-digital converter installed
in a host computer. Each AIM-16 concentrates 16 differential
analog input channels into one single-ended analog output
channel. Up to eight AIM-16s can be cascaded providing total
capacity for 128 inputs to an "8-input A/D Converter."
There are several variants of this card. These will be identified
in bold faced type in the following paragraphs.
A
high grade instrumentation amplifier provides gains from 0.5
up to 1000. Gain is software programmable channel-by-channel.
Alternatively, manual switches may be set to provide the same
gain for all inputs. If all inputs are to be the same full-scale
range, you may specify AIM-16M ("M" for manual
gain setting). This is lower priced than other models. Thermocouple
measurements require not only amplification but also cold
junction compensation and open-thermocouple or break detection.
An on-board junction-temperature sensor is normally jumpered
to the first input channel and an open or break-detect signal
is available by installing two jumpers for each channel where
break detection is desired.
Three-wire
RTD measurements are accomplished by adding two jumpers
per channel. In order to provide extended range and resolution,
an offset is introduced via a jumper. When this is done, all
channels on the card are affected. With 5 VDC offset introduced
RTD measurement range is -38° to 420°C with resolution
to approximately 0.1°. With 10 VDC offset introduced
measurement range is -200° to 680°C with resolution
of approximately 0.2°. Without the offset, range is -200°
to 680°C with resolution to about 0.4° C. If all
inputs are to be from 100-ohm RTD's then you can specify AIM-16R
and you will get a card that has been modified to provide
best possible accuracy for those RTD's.
Ratiometric
reading of a strain gage requires input to two
channels: one measures sensor excitation and the other reads
sensor output. The host computer can then compute the output
as a ratio of sensor output and a gain of 1 is used for excitation.
When AIM-16 is used with Chassis Plans Model AD12-8 or Model RAG128,
the buffered A/D converter reference voltage is available
at screw terminals on the AIM-16. That precision voltage can
provide up to 220 mA excitation current for the strain gages.
For
reading current inputs, AIM-16 has provisions
on the card for 16 precision resistors. It is only necessary
to install a resistor of proper value and to set a gain appropriate
for each current-input channel. Alternatively, if all inputs
are to be from standard 4-20 mA current transmitters, the
AIM-16I version of this card includes the resistors
and is specially set up at the factory to give full 12-bit
resolution at the A/D converter which will receive the AIM-16I
output.
For
voltage inputs, voltages should be within the
range of ±10 VDC and gains selected which are compatible
with the full-scale rating of the host A/D converter. AIM-16
uses ±12 VDC computer power as well as +5 VDC computer
power all of which is passed to the card via the A/D card.
Where the ±12 VDC computer power is noisy and/or marginally
low, a variant of AIM-16 called AIM-16P may be used.
AIM-16P contains an on-board DC-DC converter that operates
from +5 VDC computer power and provides isolated ±15
VDC for use by analog circuits on the card. This variant can
be specified for all versions of AIM-16: e.g., AIM-16IP, AIM-16RP,
etc. AIM-16 is particularly valuable in REMOTE ACCES systems
because it can be used to condition low-level signals at the
remote site and wiring that carries those signals can be kept
short to minimize chances for noise pollution. One or two
AIM-16P's can be used with Model RAG128 in a RIDACS system
as described in the REMOTE ACCES section of this web site.
UTILITY
SOFTWARE
CD
provided with AD12-8 and RAG128 contains utility software
to facilitate system integration of the two cards. Programs
on the disk include illustrated board setup instructions,
calibration procedures, linearization routines for commonly
used thermocouple types and RTD's, and sample programs
demonstrating how to make the AIM-16/AD12-8 combination
work in a system.
SPECIFICATIONS
Analog
Section
- Input
Types: Thermocouples (J,K,T,E,S,R,B), 3-wire RTD's,
strain gages, voltage, current. For RTD applications,
jumpers are provided to establish extended range
and resolution.
- Input
Impedance: 15 Megohms.
- Cold
Junction Compensation: Linear, 24.4 mV/°C.
- Amplifier
Gains: 1, 2, 10, 50, 100, 200, 400, 1000.
- Gain
Non-Linearity: ±0.005%.
- Settling
Time: AIM-16: 15µSec at gain 1-200 w/o filter.
AIM-16F: 4µSec maximum.
- Common
Mode Rejection: 125 db for gains above 100, 90 db
for gain 1.
- Temperature
Coefficient: ±5 ppm/°C.
- Overvoltage
Protection: 70 VAC p-p, 35 VDC continuous.
- Analog
Output Voltage: ±5 VDC, ±10 VDC max.
- Analog
Output Current: 5 mA max.
- Ref.
Voltage Output: Buffered +10 VDC reference voltage
from AD12-8 at up to 220 mA.
- Screw
Terminals: Accommodate 12-22 AWG size wires.
Environmental
- Operating
Temperature: 0° to 65°C.
- Storage
Temperature: -40° to +100°C.
- Humidity:
to 90% RH, non-condensing.
Power
Required
- +5
VDC @ 20 mA.
- +12
VDC @ 10 mA.
- -12
VDC @ 10 mA.
Size
Regulatory
Compliance 
Declaration of Conformity, and Test Reports are on file. Users
must use appropriate shielded cables.
| Part
Number |
Price(USD)
|
| AIM-16 |
395.00
|
| AIM-16P |
429.00
|
| AIM-16I |
425.00
|
| AIM-16M |
249.00
|
| AIM-16R |
420.00
|
View / Download Manual (in .PDF
format)
