The Model 201 was introduced in 1993. Since then, it has found its way into a remarkable variety of demanding applications,
including chromatography, thermocouple thermometry, calorimetry, electrochemistry, metrology, electrophoresis, computerized
titration, gene sequencing, particle size determination, milk grading, precision scales, 900,000-pound capacity scrap metal
weighing systems, annealing oven controls, earthquake monitoring, marine gravity measurement, wind tunnel calibration, oil
field monitoring, lighting research, rocket engine test platform instrumentation, and the Large Synoptic Survey Telescope
ultra-precision lens temperature measurement system, to name a sampling. The Model 201's flexibility, accuracy and reliability
have won it an enduring place in high resolution data acquisition.
Because the Model 201 has enjoyed such a long useful life, there is an abundance of software support available, going back to
DOS 3.1. When all the combinations of languages and operating systems are considered, the choices can be daunting. In general,
the earliest code is the simplest and clearest, if you are willing to delve into the details. The later code is more in the
spirit of Windows where the details are hidden and the functionality is available with a few clicks. Because the Model 201 is
a very flexible and generalized device, a particular point-and-click sample application may or may not support the hardware
features you wish to use. Contact us if you do not find the particular functionality you are looking for. We may have already
done it for someone else, or we may be able to provide it to you at no cost.
SPECIFICATIONS
TYPE
Serially interfaced
24-bit delta-sigma with optical isolation (these converters
have excellent noise rejection).
MONOTONICITY
24 bits at up to 50 Hz data rate.
LINEARITY
0.002% of full scale typical
at up to 50 Hz data rate.
DIFFERENTIAL INPUT RANGE
+/-5 volts or 0 to 5 volts.
DC COMMON MODE RANGE
+/-6 volts.
DC COMMON MODE REJECTION
-96 dB minimum.
RESOLUTION
16 or 24 bits, software selectable.
INPUT IMPEDANCE
100,000 megaohms typical
1013 option available
PROGRAMMABLE GAIN
1, 2, 4, 8, 16, 32, 64, or 128.
ANALOG INPUTS
6 fully differential, protected to 60 volts, expandable to 96 channels using optional multiplexers
DIGITAL INPUTS
8-bits, contact closure or
5-volt logic compatible
DIGITAL OUTPUTS
4 optically isolated lines plus
8 latched logic outputs
POWER REQUIREMENT
+11.5 to +50 VDC
regulated or unregulated
TYPICAL POWER CONSUMPTION
up to +24 VDC power supply voltage
operation
18 mA
standby
14 mA
sleep
2 mA
add 3 mA to each at +50 VDC
SIZE
5 x 6.5 x 0.8"
board only
5.6 x 7 x 1.8"
in optional enclosure
SPEED
The Model 201 has a programmable
conversion rate which also
determines the cut-off frequency of
the low-pass filter. Representative
values are given below. Effective
resolution is 24 bits minus RMS
noise in bits. Effective resolution
may be reduced at gains above x4.
DATA RATE
10 Hz
30 Hz
100 Hz
300 Hz
CUT-OFF FREQUENCY (-3 dB)
2.6 Hz
7.9 Hz
26 Hz
79 Hz
EFFECTIVE RESOLUTION (BITS)
22
20
19
15
SETTLING TIME (SECONDS)
0.4
0.13
0.04
0.013
SERIAL INTERFACE
RS232, optically isolated, full
duplex. Programmable from 300 to 9600
Baud. Checksum transmitted on request.
OTHER FEATURES
Also under software control are
signal averaging and variable input
filtration. The Model 201 can operate
in polled or scanning mode. In polled
mode, individual readings are
transmitted on request. In scanning
mode, a pre-defined block of data is
transmitted at a preset interval.
Sleep mode drastically reduces power consumption.
EXPANSION CAPABILITY
A stacking expansion board can hold
memory, additional A/D or D/A
converters, or additional digital
input and output.
CUSTOM MODIFICATIONS
The Model 201 can be custom programmed to perform a wide variety of tasks. If you do not see a particular feature here, call
for a quotation. With a combination of custom hardware and software, the Model 201 can be optimized for process control, remote
data logging, chromatography, or other application.
OPTIONS
Lower noise and thermal drift input amplifier option $25
Custom ID numbers for software protection (contact factory for cost)
The Lawson Labs, Inc. Model 201-5 is a stacking expansion card to
provide analog output capability for the Model 201 24-bit Data
Acquisition System. The digital-to-analog converter (DAC) card
is available in two- or five-channel versions. The standard range
is 0 to 5 VDC. The first two channels can be set at the factory for
+/-5 or 0 to 10 volts or other custom ranges. Resolution is
programmable up to a maximum of 16 bits. The Model 201-5 is intended
for DC or very low frequency application.
Because the precision reference on the Model 201 is used to generate
the output voltages, long-term output stability is excellent.
Voltages are set using the Model 201's expansion output commands.
Adding a DAC card will not affect the other functions of the Model
201. The Model 201, itself, does not need to be altered to accept the
stacking expansion card.
ANALOG OUTPUT CHANNELS
2 (Model 201-5-2) or 5 (Model 201-5-5)
OUTPUT VOLTAGE RANGE
Standard: 0 to 5 Volts
Optional: +/-5, or 0 to 10 Volts
other ranges available, consult factory
RESOLUTION
Programmable, up to 1 part in 65536
ACCURACY
0.1% of Full Scale
(0.03% of Full Scale with software offset correction)
premium low-offset versions available
LINEARITY
0.01% of full scale at 25 °C
RIPPLE
5 volt range, 1 part in 10,000 resolution
1 mV RMS, typical
OUTPUT DRIVE CURRENT
5 mA minimum
TEMPERATURE COEFFICENT
50 ppm per °C, typical (premium versions available)
RESPONSE TIME CONSTANT
0.3 Seconds
CURRENT REQUIREMENT
5-Channel
14 mA in sleep mode
18 mA in operation
(plus output load currents)
2-Channel
12 mA in sleep mode
14 mA in operation
(plus output load currents)
SIZE
4.4 x 4.3 x 0.6 inches
WEIGHT
3 ounces
user manual
HTML format
view online
( click link to view manual in your browser window )
download archive
( click link to download manual archive to your PC disk drive )
TEXT format
view online
( click link to view manual in your browser window )
download archive
( click link to download manual archive to your PC disk drive )
Specs and Usage
We recommend that you look here first concerning questions related to the Model201.
The DLL's available within the downloadable sample applications (both end-user and developer) may not be the most recent. The DLLs
linked to here are the most recent, so after downloading a sample app, be sure to replace the DLL that is archived with it with the
most recent one ( with the same name ) linked to abvoe.
