Isolated Analog Signal Conditioning Products
S C M 5 B
SCM5B38
Strain Gage Input Modules, Wide Bandwidth
Description
Each SCM5B38 Strain Gage input module provides a single channel of
strain gage input which is filtered, isolated, amplified, and converted to a
high-level analog voltage output (Figure 1). This voltage output is logic
switch controlled, which allows these modules to share a common analog
bus without the re uirement of external multiplexers.
The SCM5B modules are designed with a completely isolated computer
side circuit which can be oated to
from Power ommon, pin .
This complete isolation means that no connection is re uired between I O
Common and Power Common for proper operation of the output switch.
If desired, the output switch can be turned on continuously by simply
connecting pin , the Read nable pin, to I O ommon, pin .
The S
B can interface to full bridge or half bridge transducers with a
nominal resistance of
to
. A matched pair of bridge completion
resistors to m at
excitation allows use of low cost half bridge
or uarter bridge transducers Figures , , . The
H bandwidth
allows measurement of high speed processes such as vibration analysis.
Strain gage excitation is provided from the module by a very stable
or 3.333V source. The excitation supply is fully isolated, allowing the
amplifier inputs to operate over the full range of the excitation voltage.
This feature offers significant exibility in real world applications. Full
scale sensitivities of 2mV/V, 3mV/V or 10mV/V are offered as standard.
With 10V excitation, this results in ± 20mV, ± 30mV or ± 100mV full scale
input range producing ± 5V full scale output.
The input signal is processed through a wide bandwidth pre amplifier
on the field side of the isolation barrier. After amplification, the input signal is chopped by a proprietary chopper circuit. Isolation is provided by
transformer coupling, again using a proprietary technique to suppress
F i g u r e 1 : S C M 5 B 3 8 B l o ck
Features
Interfaces to
Thru
, Full Bridge,
Half-Bridge, or Quarter-Bridge Strain Gages
• High-Level Voltage Output
• 1500Vrms Transformer Isolation
• ANSI/IEEE C37.90.1 Transient Protection
• Input Protected to 240VAC Continuous
• Fully Isolated Excitation Supply
• 100dB CMR
• 10kHz Signal Bandwidth
• ± 0.03% Accuracy
• ± 0.01% Linearity
Drift
SA
S ertified
• CE and ATEX Compliant
• Mix and Match SCM5B Types on Backpanel
transmission of common mode spikes or surges. The module is powered
from +5VDC, ± 5%.
Special input circuits on the SCM5B38 module provide protection of the
signal inputs and the isolated excitation supply up to 240VAC.
D ia g r a m
2 2
©1995-2017 Dataforth Corporation, All Rights Reserved
For information call 800-444-7644
ISO9001:2008-Registered QMS
Specifications
Typical❇ at TA
Module
Input Range
Input Bias Current
Input Resistance
Normal
Power Off
Overload
Signal Input Protection
Continuous
Transient
Excitation Output (-02, -04, -05, -07)
Load Resistance
Excitation Output (-01, -03, -06)
Load Resistance
Excitation Load Regulation
xcitation Stability
Half Bridge Voltage Level (-04)
Half Bridge Voltage Level (-03)
Isolated Excitation Protection
Continuous
Transient
CMV, Input to Output
Continuous
Transient
CMR (50 or 60Hz)
NMR (– 3dB at 10kHz)
Accuracy(2)
Linearity
Stability
Input Offset
Output Offset
Gain
Noise
Input, 0.1 to 10Hz
Output, 100kHz
Bandwidth, – 3dB
Rise Time, 10 to 90% Span
Settling Time, to 0.1%
Output Range
Output Resistance
Output Protection
Output Selection Time
(to ± 1mV of VOUT)
Output Current Limit
Output nable ontrol
Max Logic “0”
Min Logic “1”
Max Logic “1”
Input Current “0,1”
Power Supply Voltage
Power Supply Current
Power Supply Sensitivity
Mechanical Dimensions
(h)(w)(d)
Environmental
Operating Temperature Range
Storage Temperature Range
Relative Humidity
Emissions EN61000-6-4
Radiated, Conducted
Immunity EN61000-6-2
RF
ESD, EFT
and
Ordering Information
D power
Full Bridge
SCM5B38-01,-02,-05,-06,-07
± 10mV to ± 100mV
± 0.3nA
Half Bridge
SCM5B38-03,-04
*
*
Model
(10kHz)
SCM5B38-01
SCM5B38-02
SCM5B38-03
SCM5B38-04
SCM5B38-05
SCM5B38-06
SCM5B38-07
*
*
*
240Vrms max
ANSI/IEEE C37.90.1
+10V ± 3mV
to
+3.333V ± 2mV
to
± 5ppm/mA
ppm
NA
NA
S C M 5 B
S C M 5 B
Isolated Analog Signal Conditioning Products
*
*
*
*
Type
Bridge
Input
Full
Full
Half
Half
Full
Full
Full
Output
citation Sens. Range†
Input Range
– 10mV to +10mV
+3.333V 3mV/V
– 30mV to +30mV
+10.0V 3mV/V
– 10mV to +10mV
+3.333V 3mV/V
– 30mV to +30mV
+10.0V 3mV/V
– 20mV to +20mV
+10.0V 2mV/V
– 33.3mV to +33.3mV +3.333V 10mV/V
– 100mV to +100mV +10.0V 10mV/V
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
Output Ranges Available
†
*
*
Output Range Part o u fi
*
*
+5V ± 1mV
+1.667V ± 1mV
240Vrms max
ANSI/IEEE C37.90.1
1. – 5V to +5V
2. – 10V to +10V
NONE
D
am e
SCM5B38-01
SCM5B38-01D
*
*
1500Vrms max
ANSI/IEEE C37.90.1
100dB
dB per Decade above H
± 0.03% Span
± 0.01% Span
*
*
*
*
*
*
*
*
ppm of Reading
*
. rms
10mVp-p
10kHz
s
s
See Ordering Information
rms
*
*
F i g u r e 2 : F u l l B r i d g e C o n n e ct i o n
*
*
*
*
Continuous Short to Ground
s at load = 0 to 2000pF
*
*
± 8mA
+0.8V
+2.4V
+36V
. A
+5VDC ± 5%
170mA Full Exc. Load,
70mA No Exc. Load
RTI(3)
2.28” x 2.26” x 0.60”
(58mm x 57mm x 15mm)
to
to
0 to 95% Noncondensing
ISM, Group 1
Class A
ISM, Group 1
Performance A ± 0.5% Span Error
Performance B
ontact factory or your local Dataforth sales office for maximum values.
NOTES:
* Same as – 01, – 02, – 05, – 06, – 07 modules.
Strain element. Includes linearity, hysteresis and repeatability. RTI Referenced to input.
*
*
*
*
*
*
*
F i g u r e 3 : H a l f B r i d g e C o n n e ct i o n
*
*
*
*
*
*
*
*
*
*
❇
F i g u r e 4 : Q u a r t e r B r i d g e C o n n e ct i o n
Visit our website www.dataforth.com
©1995-2017 Dataforth Corporation, All Rights Reserved
2 3
ISO9001:2008-Registered QMS