SCM5B38 (Wide BW): Strain Gage Input Modules, Wide Bandwidth. Dataforth

Specialists in data acquisition, signal conditioning and data communication

English

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 requirement of external multiplexers.

The SCM5B modules are designed with a completely isolated computer side circuit which can be floated to ±50V from Power Common, pin 16. This complete isolation means that no connection is required 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 22, the Read-Enable pin, to I/O Common, pin 19.

The SCM5B38 can interface to full-bridge or half-bridge transducers with a nominal resistance of 100 Ohm to 10 kOhm. A matched pair of bridge-completion resistors (to ±1mV at +10V excitation) allows use of low cost half-bridge or quarter-bridge transducers (Figures 2, 3, 4). The 10kHz bandwidth allows measurement of high speed processes such as vibration analysis.

Strain gage excitation is provided from the module by a very stable 10V 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 flexibility 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 pre-amplifier on the field side of the isolation barrier. This pre-amplifier has a gain-bandwidth product of 5MHz and is bandwidth limited to 10kHz. 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 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.

Interfaces to 100 Ohm Thru 10 kOhm, 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
±1µV/°C Drift
CSA Certified, FM Approved, CE and ATEX Compliant
Mix and Match SCM5B Types on Backpanel

Strain Gage Input Modules, Wide Bandwidth

SCM5B38 (Wide BW) Devices

Part Number	Excitation Voltage	Sensitivity	Input Configuration	Input Range	Output Range	Bandwidth	Mechanical Format
SCM5B38-01 Order Now	3.333 V	3 mV/V	Full Bridge	-10 to +10 mV	-5 to +5 V	10 kHz	Modular plug-in-board
SCM5B38-01D Order Now	3.333 V	3 mV/V	Full Bridge	-10 to +10 mV	-10 to +10 V	10 kHz	Modular plug-in-board
SCM5B38-02 Order Now	10.0 V	3 mV/V	Full Bridge	-30 to +30 mV	-5 to +5 V	10 kHz	Modular plug-in-board
SCM5B38-02D Order Now	10.0 V	3 mV/V	Full Bridge	-30 to +30 mV	-10 to +10 V	10 kHz	Modular plug-in-board
SCM5B38-03 Order Now	3.333 V	3 mV/V	Half Bridge	-10 to +10 mV	-5 to +5 V	10 kHz	Modular plug-in-board
SCM5B38-03D Order Now	3.333 V	3 mV/V	Half Bridge	-10 to +10 mV	-10 to +10 V	10 kHz	Modular plug-in-board
SCM5B38-04 Order Now	10.0 V	3 mV/V	Half Bridge	-30 to +30 mV	-5 to +5 V	10 kHz	Modular plug-in-board
SCM5B38-04D Order Now	10.0 V	3 mV/V	Half Bridge	-30 to +30 mV	-10 to +10 V	10 kHz	Modular plug-in-board
SCM5B38-05 Order Now	10.0 V	2 mV/V	Full Bridge	-20 to +20 mV	-5 to +5 V	10 kHz	Modular plug-in-board
SCM5B38-05D Order Now	10.0 V	2 mV/V	Full Bridge	-20 to +20 mV	-10 to +10 V	10 kHz	Modular plug-in-board
SCM5B38-06 Order Now	3.333 V	10 mV/V	Full Bridge	-33.3 to +33.3 mV	-5 to +5 V	10 kHz	Modular plug-in-board
SCM5B38-06D Order Now	3.333 V	10 mV/V	Full Bridge	-33.3 to +33.3 mV	-10 to +10 V	10 kHz	Modular plug-in-board
SCM5B38-07 Order Now	10.0 V	10 mV/V	Full Bridge	-100 to +100 mV	-5 to +5 V	10 kHz	Modular plug-in-board
SCM5B38-07D Order Now	10.0 V	10 mV/V	Full Bridge	-100 to +100 mV	-10 to +10 V	10 kHz	Modular plug-in-board

Frequently Asked Questions

Can Dataforth provide calibration reports for modules I purchased?

Yes we can provide calibration reports for the modules that you purchased.

You can either
a) visit https://www.dataforth.com/TestDataReport.aspx to search for Test Report Datasheets by Serial Number or
b) you can send us a list of model numbers and their serial numbers to support@dataforth.com

Analog Devices announced a last time buy and discontinuance of their signal conditioning modules. Can I replace them with Dataforth signal conditioning modules?

Yes, in general, Dataforth signal conditioning modules are a direct replacement for all Analog Devices signal conditioning modules. e.g. "SCM5B35-xx: Linearized 4-Wire RTD Input Modules" will replace Analog Devices "5B35: Isolated 4 Wire RTD Input Signal Conditioning Module".

Please note that Dataforth signal conditioning modules are RoHS II compliant.

What is the recommended power supply for Dataforth SCM5B and 8B modules?

The recommended power supply for the Dataforth SCM5B and 8B modules are the linear power supplies in our SCMXPRT/SCMXPRE series. The SCMXPRT/SCMXPRE power supplies output 5V and have options for 1A output current (SCMXPRT-001) or 3A output current (SCMXPRT-003).

The SCMXPRE series is identical to its SCMXPRT counterpart, but is configured for European voltage standards.

The SCMXPRT-001/SCMXPRE-001 both have the option for DIN rail mounting as well (SCMXPRT-001D/SCMXPRE-001D).

Other power supplies that meet that power requirements of the SCM5B and 8B modules can be used as well, but it is strongly recommended to use a linear power supply rather than a switch-mode power supply. Switching power supplies can add noise artifacts to the output of your modules.

If I purchase a backplane with no CJC, will I still be able to use modules that require the CJC enable jumper to be installed?

Yes. Backplanes with no CJC will still come with the CJC enable installed on the backplane.

What does “sensitivity” mean on my strain gage input module?

The sensitivity is listed on the datasheet to help determine what strain gages/load cells will be compatible with that module. Strain gages do not have a specific voltage output range (i.e. -30mV to 30mV) but rather a voltage output range that varies depending on the excitation voltage applied to the strain gage (its "sensitivity"). Since our strain gage modules have a fixed voltage input range and a fixed excitation voltage, the sensitivity is the most reliable way to determine if a strain gage is compatible with our module.

For example, a load cell with a 3mV/V sensitivity will output 30mV at full scale with a 10V excitation voltage, because 3mV/V * 10 V = 30mV. A signal conditioner with a 10V excitation and a -30mV to 30mV input range will be compatible with a load cell of 3mV/V sensitivity.

Is the calibration of Dataforth modules traceable to NIST standards?

Yes, calibration of Dataforth modules is traceable to NIST standards.

Do you have any SCM5B modules with a 50kHz bandwidth?

None of our standard SCM5B modules have a 50kHz bandwidth. However, it is possible to order a custom SCM5B module with 50kHz bandwidth. Keep in mind that new customs require a 10 pc minimum order and are subject to extra design fees.

Do you have an MTBF figure for the SCM5B39? What are the main failure modes?

The failure rate calculations for our SCM5B modules can be found in our application note AN503: https://www.dataforth.com/catalog/pdf/an503.pdf

There are no dominant failure modes.

I just received an SCMPB01 back panel. How should I configure jumpers J1 through J4 for my application?

The factory configuration for jumpers J1 through J4 is the optimal configuration for most applications. If for some reason this jumper configuration will not work/is not working in your application, see our application note AN502 "Ground Connections and Host System Interfaces" for other valid jumper configurations and what situations you would use them.

Where can I find the MTBF of my module?

Information on MTBF for SCM5B, SCM7B, 8B and DSCA is available on our website. Please see application note AN802 for more details. Application notes can be found under the "Literature" tab on the top navigation bar.

Can I supply fixed resistors to a full bridge SCM5B38 module to make my half bridge or quarter bridge strain gauge work properly with the module?

Yes, the quarter and half bridge SCM5B38 modules have the bridge completion resistors across terminals +EXC and -IN and -EXC and -IN internal to the module. Applying fixed resistors across the same terminals will have the same effect on a full bridge SCM5B38.

On the SCM5B modules, what is the purpose of pin 18 (Vin), why is it tied to pin 20 (Vout)? Doesn't Vout provide the output by itself?

Vout is used with input modules, which are all the SCM5B models except for the SCM5B39 and SCM5B49. Vin is used for output modules, SCM5B39 and SCM5B49.

The reason for doing this is because input modules acquire a signal from the field side, and then output a corresponding signal to the system side. On the contrary, output modules acquire a signal from the system side, and then output a corresponding signal to the field side. Since SCM5B backplanes are designed for all channels to accommodate either an input or an output module, the terminal/pin that you would normally get your output signal from if you were using an input module is the same terminal/pin that you would be feeding your input signal to if you were using an output module.

What is the required resistance for jumpers J1 through J4 on my SCM5B backpanel?

J1-J4 on the SCM5B backpanels are jumper cables, so they should have 0 ohm resistance.

Should I ground my sensor wire shield to the 10-32 ground post on the SCMPB01?

It is not recommended to ground the sensor wire shield to the 10-32 ground post on the SCMPB01 because that is the system side ground, while the sensor wire is on the field side. The sensor wire shield should be grounded to the field side ground, which varies based on the signal conditioner you are using. Please see the "Shield Grounding" application note for more information.

Can I use an SCM5B module with my OM5-BP-SKT-C?

Yes, any of our SCM5B modules are able to be mounted and operated on Omega's OM5-BP-SKT-C board.

Will the isolation on the SCM5B modules support a discharge of 1500VDC without damaging anything connected to the output?

Yes, the SCM5B modules are isolated up to 1500 Vrms, which means that if the common mode voltage between the field side and system side is limited to 1500Vrms, the device will be protected.

However, the input protection for SCM5B modules (i.e., the voltage across the +IN and -IN input terminals) is 240Vrms max.

How do I convert an RMS voltage to its corresponding peak voltage?

To convert an RMS voltage to its corresponding peak voltage, you simply take the RMS voltage value and multiply it by the square root of 2, or roughly 1.414.

For example, 1500Vrms corresponds to a peak voltage of 1500 * 1.414 = 2121 Vp

If the input range of my signal conditioner is -1V to +1V and the output range is 0 to 10V, does this mean that it ignores polarity?

A signal conditioner with these I/O ranges does not mean that the module ignores the polarity of your voltage input. The output of voltage input modules are scaled linearly, meaning an input of -1V would correspond to an output of 0V, an input of 0V would correspond to an output of 5V, an input of +1V would correspond to an output of 10V, and so on.

Do I need to purchase the SCMXCJC with my SCMPB03?

No, the SCMPB03 comes with the CJC built into the backpanel.

Do SCM5B modules with outputs scaled up to 10V have separate power requirements from their 5V counterparts?

No, all SCM5B modules have the same power requirements (5VDC) regardless of their I/O specifications. The power supply current draw of different products in the SCM5B line may vary.

How does the load resistance of a module affect the noise at the output?

Noise at the output of a module is independent of load resistance.

Can I use the SCMXBEFE and SCMXSE accessories to make my SCMPB01/2 DIN rail mountable?

No, converting any of the 16 channel SCM5B backplanes to something DIN rail mountable is a much more involved process than the SCMPB03/04. If you would like a 16 channel SCM5B backplane that can mount on a DIN rail you must purchase an SCMPB01-2, SCMPB01-3, SCMPB02-2 or SCMPB02-3.

Is the SCM5B40-06 sensitive to being soldered into a board? Would soldering it damage the part?

We do not recommend soldering the SCM5B pins to a board as it could potentially damage the module. Soldering the pins would also void the warranty.

Many sockets are available which accept the mounting pins. TE Connectivity / AMP part number 50865-5 is an example of these sockets and any equivalent part will work as well.

Is the SCMXPRT-003 DIN rail mountable?

The SCMXPRT-001 has an option for DIN rail mounting (part number: SCMXPRT-001D) but the SCMXPRT-003 does not. Instead, it can be mounted on the SCMXRK-002 which is a 19 inch metal rack for mounting the SCMXPRT-003 as well as various Dataforth backpanels and the SCMXIF interface board.

What types of DIN rails does the DIN rail mounting of the SCMPB04 attach to?

The DIN rail mounting of the SCMPB04 can mount to DIN rail types EN 50022-35x7.5, EN 50022-35x15, EN 50035-G32. These can be purchased as part numbers SCMXRAIL1-XX, SCMXRAIL2-XX, pr SCMXRAIL3-XX where XX is specified as the length of the rail in meters.

Can the DIN rail mounting hardware be easily removed from the SCMPB04?

Yes, the DIN rail mounting hardware for the SCMPB04 can be easily detached and reattached from the board.

Where can I find the pinout of my SCM5B module?

Please see the SCM5B Module Dimensions and Pinouts link from the SCM5B section of our website: https://www.dataforth.com/catalog/pdf/scm5bdim.pdf

You can also find the module dimensions and pinouts in our product catalog.

Can SCM5B modules be hot swapped?

Not just SCM5B modules, but any signal conditioning module series and MAQ20 I/O modules can be hot swapped. A minimal amount of signal settling time may result, but there will be no damage to the device.

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Model Number	Input Range	Output Range	Bandwidth	Sensor Type	Status*	Comments
SCM5B38-1012 Request Quote	-120mV TO +120mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1037 Request Quote	-30mV TO +30mV	-5V TO +5V	25HZ	STRAIN GAGE	QU	10V Exc., Full Bridge
SCM5B38-1038 Request Quote	-30mV TO +30mV	-5V TO +5V	50HZ	STRAIN GAGE	QU	10V Exc., Full Bridge
SCM5B38-1039 Request Quote	-30mV TO +30mV	-5V TO +5V	100HZ	STRAIN GAGE	QU	10V Exc., Full Bridge
SCM5B38-1040 Request Quote	-30mV TO +30mV	-5V TO +5V	200HZ	STRAIN GAGE	QU	10V Exc., Full Bridge
SCM5B38-1059 Request Quote	-10mV TO +10mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	5V Excitation, Full Bridge
SCM5B38-1083 Request Quote	-30mV TO +30mV	-5V TO +5V	120HZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1084 Request Quote	-20mV TO +20mV	-5V TO +5V	120HZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1087 Request Quote	-10mV TO +10mV	-5V TO +5V	200HZ	STRAIN GAGE	PR	3.333V Excitation, Full Bridge
SCM5B38-1088 Request Quote	-30mV TO +30mV	0V TO +5V	4KHZ	STRAIN GAGE	QU	10V Exc., Full Bridge
SCM5B38-1126 Request Quote	-30mV TO +30mV	0V TO +5V	10KHZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1128 Request Quote	-20mV TO +20mV	0V TO +5V	120HZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1129 Request Quote	-20mV TO +20mV	-5V TO +5V	30HZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1132 Request Quote	-5mV TO +5mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1134 Request Quote	-100 TO +100mV	-5V TO +5V	2.5KHZ	STRAIN GAGE	PR	10V Excitation, Full Bridge
SCM5B38-1146 Request Quote	0mV TO +10mV	-5V TO +5V	4HZ	STRAIN GAGE	PR	10V Exc, 1mV/V Sensitivity, Full Bridge
SCM5B38-1150 Request Quote	-10mV TO +10mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	2V Exc, 5mV/V Sensitivity, Full Bridge
SCM5B38-1151 Request Quote	-20mV TO +20mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	2V Exc, 10mV/V Sensitivity, Full Bridge
SCM5B38-1156 Request Quote	-70mV TO +70mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	10V Excitation, 7mV/V Sensitivity, Full Bridge
SCM5B38-1161 Request Quote	-10mV TO +10mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	3.333V Exc, 3mV/V Sensitivity, Full Bridge
SCM5B38-1184 Request Quote	-10mV TO +10mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	10V Exc., 1mV/V Sensitivity, Full Bridge
SCM5B38-1212 Request Quote	-20mV TO +20mV	0V TO +5V	4HZ	STRAIN GAGE	PR	10V Exc., Full Bridge
SCM5B38-1221 Request Quote	-10mV TO +10mV	-5V TO +5V	1KHZ	STRAIN GAGE	QU	10V Exc., 4 pole butterworth, Full Bridge
SCM5B38-1222 Request Quote	-20mV TO +20mV	-5V TO +5V	1650HZ	STRAIN GAGE	PT	10V Exc., 4 pole butterworth, Full Bridge
SCM5B38-1223 Request Quote	-200mV TO +200mV	-5V TO +5V	1650HZ	STRAIN GAGE	QU	10V Exc., 4 pole butterworth, Full Bridge
SCM5B38-1232 Request Quote	0V TO +30mV	-5V TO +5V	4HZ	STRAIN GAGE	PR	10V Exc., Full Bridge
SCM5B38-1235 Request Quote	-10mV TO +10mV	-5V TO +5V	10KHZ	STRAIN GAGE	QU	same as SCM5B38-1184, Full Bridge
SCM5B38-1260 Request Quote	-100mV TO +100mV	-5V TO +5V	20KHZ	STRAIN GAGE	QU	5V Excitation, Full Bridge
SCM5B38-1264 Request Quote	-5mV TO +5mV	-5V TO +5V	10KHZ	STRAIN GAGE	QU	5V Excitation, half bridge
SCM5B38-1284 Request Quote	-30mV TO +30mV	-5V TO +5V	10HZ	STRAIN GAGE	PR	10V Exc., full bridge, min phase req.
SCM5B38-1285 Request Quote	-30mV TO +30mV	-5V TO +5V	20HZ	STRAIN GAGE	PR	10V Exc., full bridge, min phase req.
SCM5B38-1286 Request Quote	-10mV TO +10mV	-5V TO +5V	100HZ	STRAIN GAGE	QU	10V Excitation, full bridge
SCM5B38-1287 Request Quote	-166mV TO 166mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	3.333V Excitation, half bridge, 50mV/V
SCM5B38-1289 Request Quote	-30mV TO +30mV	-5V TO +5V	800HZ	STRAIN GAGE	PR	10V Excitation, full bridge, 3mV/V
SCM5B38-1290 Request Quote	-20mV TO +20mV	-5V TO +5V	800HZ	STRAIN GAGE	PR	10V Excitation, full bridge, 2mV/V
SCM5B38-1298 Request Quote	-2.5mV TO +2.5mV	-5V TO +5V	5KHZ	STRAIN GAGE	PR	3.333V Exc., Full Bridge
SCM5B38-1327 Request Quote	-40mV TO +40mV	-5V TO +5V	4HZ	STRAIN GAGE	PR	10Vexc., Full Bridge, 4mV/V
SCM5B38-1328 Request Quote	-10mV TO +10mV	-10V TO +10V	10KHZ	STRAIN GAGE	QU	10Vexc., Full Bridge, 1mV/V
SCM5B38-1334 Request Quote	-10mV TO +10mV	-10V TO +10V	2.5KHZ	STRAIN GAGE	PR	10V Exc., 1mV/V Sensitivity, Full Bridge
SCM5B38-1340 Request Quote	-1V TO +1V	-5V TO +5V	4HZ	STRAIN GAGE	PR	10Vexc., Half Bridge, 100mV/V
SCM5B38-1345 Request Quote	-30mV TO +30mV	-5V TO +5V	4HZ	STRAIN GAGE	PR	10V Exc., +/-0.03% Accurate, Full Bridge
SCM5B38-1499 Request Quote	-250mV TO +250mV	-5V TO +5V	10kHz	STRAIN GAGE	PR	5V Exc., 50mV/V Sensitivity, Full Bridge
SCM5B38-1512 Request Quote	-10mV TO +10mV	-5V TO +5V	10Hz	STRAIN GAGE	PR	3.333V Exc., 3mV/V Sensitivity, Full Bridge
SCM5B38-1560 Request Quote	-20mV TO +20mV	-5V TO +5V	30Hz	STRAIN GAGE	PR	10V Exc., 2mV/V Sensitivity, HALF BRIDGE INPUT
SCM5B38-1571 Request Quote	-50mV TO +50mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	10V Excitation, full bridge, 5mV/V
SCM5B38-1581 Request Quote	-20mV TO +20mV	-10V TO +10V	250HZ	STRAIN GAGE	PR	10V Excitation, full bridge, 2mV/V
SCM5B38-1593 Request Quote	-10mV TO +10mV	-5V TO +5V	2kHz	STRAIN GAGE	PR	10V Excitation, full bridge, 1mV/V
SCM5B38-1597 Request Quote	-50mV TO +50mV	-5V TO +5V	10kHz	STRAIN GAGE	PR	10V Exc., 5mV/V Sensitivity, Full Bridge
SCM5B38-1619 Request Quote	-20mV TO +20mV	-5V TO +5V	10kHz	STRAIN GAGE	PR	Same as SCM5B38-05 with different Osc. Frequency and filter
SCM5B38-1620 Request Quote	-10mV TO +10mV	-5V TO +5V	10KHZ	STRAIN GAGE	PR	Similar to 5B38-1184, Full Bridge, Bridge Impedance 4.5kOhm
SCM5B38-1627 Request Quote	-30mV TO +30mV	-10V TO +10V	100HZ	STRAIN GAGE	PR	10V Excitation, full bridge, 3mV/V
SCM5B38-1633 Request Quote	-20mV TO +20mV	-10V TO +10V	2KHZ	STRAIN GAGE	PR	10V Excitation, full bridge, 2mV/V
SCM5B38-1785 Request Quote	-50mV TO +50mV	-10V TO +10V	10kHz	STRAIN GAGE	PR	10V Exc., 5mV/V Sensitivity, Full Bridge
SCM5B38-1788 Request Quote	-100mV TO +100mV	-5V TO +5V	4Hz	STRAIN GAGE	PR	Excitation = 50uA
SCM5B38-1851 Request Quote	-100mV TO +100mV	-5V TO +5V	4Hz	STRAIN GAGE	PR	Excitation = 10uA
SCM5B38-1852 Request Quote	-30mV TO +30mV	-5V TO +5V	10kHz	STRAIN GAGE	PR	SCM5B38-02 with improved vibration and shock resistance
SCM5B38-1854 Request Quote	-30mV TO +30mV	-5V TO +5V	100Hz	STRAIN GAGE	PR	Bessel (Thomson) filter