SCM7B Series: Isolated Process Control Signal Conditioning Products. Dataforth

Isolated Process Control Signal Conditioning Products

SCM7B MODULES

7B Process Control Signal ConditioningEach Dataforth 7B module provides a single channel of isolated analog input or output.

  • Input modules accept analog voltage or current signals from all types of field sensors and sources; they filter, isolate, amplify, linearize, and convert the input signals to high-level analog outputs for use in process control systems
  • Output modules accept high-level analog voltage signals from a process control system, then buffer, isolate, filter, and amplify them before providing current or voltage output to field devices
All 7B modules are CSA C/US certified and CE and ATEX compliant.

Accessories include a complete selection of backpanels, DIN rail mounting options, interface cables, mounting racks, power supplies, and other accessory items.

CUSTOM SIGNAL CONDITIONING

Custom modules are available: consult factory for minimum quantity and pricing details on custom input ranges, output ranges, bandwidth, and other key parameters.

Features

  • ±0.03% Accuracy (Typical)
  • ±0.01% Linearity
  • 1500Vrms Transformer Isolation & 240Vrms Field-side Protection
  • ANSI/IEEE C37.90.1 Transient Protection
  • Wide Supply Voltage, 14 to 35VDC
  • 5-Pole Low-Pass Filtering
  • Low Peak and RMS Noise
  • Low Drift Input Circuitry for Long-Term Stability
  • Up to 160dB CMRR
  • 85dB NMR at 60Hz, 80dB at 50Hz
  • -40°C to +85°C Operating Temperature
  • Backpanels Allow Use of Industry Standard Digital I/O, Solid State Relay Modules
  • DIN Rail Mounting
  • CSA C/US Certified (Class I, Division 2, Groups A, B, C, D)
  • CE and ATEX Compliant
  • Manufactured per RoHS Directive (EU) 2015/863 (RoHS 3)

FAQ

Can Dataforth analog modules be used in high vibration environments? If so, what type of testing or certification was completed?
SCM5B, SCM7B, 8B SensorLex, and DSCA modules are well suited for use in high vibration environments. These modules and their associated accessories have undergone testing for random vibration, shock, and swept sine wave vibration. Details of each of these testing methods are provided below: Random Vibration (Operating): ○ MIL-STD 202G, Method 214A, Condition 1 - Frequency Range: 50-2000Hz, flat spectrum - Vibration Intensity: 7.56 Grms - Duration: 10min/axis (X, Y, Z) Shock (Operating): ○ MIL-STD-810F, Method 516.5 - Pulse Shape: Sawtooth - Test Level: 30G - Duration 11ms - Orientation: +/-X, +/-Y, +/-Z Swept Sine Vibration (Operating) ○ MIL-STD-810G, Method 514.6, modified - Frequency Range: 10-2000Hz - Vibration Intensity: 5Gp-p - Sweep Rate: 1 octave/min - Orientation: X, Y, Z Declaration of conformity for the above-listed tests can be provided upon customer request. Please contact customer service if a copy of the declaration is needed.
Due to resource constraints on my computer, I'm unable to open the three dimensional CAD models provided on your website. Does Dataforth provide two demensional CAD models for download as well?
Two dimensional CAD models can be generated upon customer request. Please contact Customer Service for assistance.
What does it mean when an input module has for example a 3kHz bandwidth?
A 3kHz bandwidth on an input module means it can accept voltages from DC to 3000Hz. Any frequency higher than that and the signal will start to be attenuated by the filter at the input.
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.
What does "Response time, 90% span" mean on the datasheet for my module?
Normally, a response time figure refers to how quickly a module's output can "respond" to a change in the input signal. "Response time, 90% span" refers to how fast a module can adjust its output when a step signal is applied at the input, where the magnitude of this step input is 90% of the input span of the module.
How will the measurement of my thermocouple module be affected if I use a backplane without CJC?
CJC is mandatory when using thermocouple input modules, or else you will not get an accurate measurement. Make sure to always purchase a backplane with CJC installed if you are using a thermocouple input module.
Do I need to specify what thermocouple modules I am ordering when I purchase a backplane with CJC installed?
No, the CJC will work for all thermocouple modules that can be mounted to that backplane.
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.
Is the calibration of Dataforth modules traceable to NIST standards?
Yes, calibration of Dataforth modules is traceable to NIST standards.
Does Dataforth have any options for thermistor input?
Thermistor interface has never been designed for SCM7B, 8B, DSCT, or MAQ20 product lines. However, we do have some custom products in the SCM5B line that can accept thermistor interface. Any SCM5B36, SCM7B36, 8B36, DSCA36, DSCT36 module with potentiometer input 0-10kohm may also be suitable for some sensors.
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.
Is it possible to utilize remote CJC with the 7B47 modules?
SCM7B47 modules are designed to interface the 100k NTC thermistors which are installed on the SCM7B backpanels. Therefore, remote CJC is only possible if the 100k thermistor is replaced with a fixed resistor which requires a custom backpanel.
Is the SCM7B32-01 a suitable replacement for the Analog Devices 7B32-01-1?
Yes, the SCM7B32-01 is a direct replacement for the 7B32-01-1. Any application that uses a 7B32-01-1 will support an SCM7B32-01, and vice versa.
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.
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.
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.
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.
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
Do SCM7BP02 and SCM7BP04 have CJC sensors installed by default?
All SCM7B backpanels, including SCM7BP02 and SCM7BP04 have CJC sensors installed by default in every field input terminal in every channel. There is no separate model number for including CJC sensors as in SCM5B and 8B backpanels.

KEYWORDS/PHRASES: SCM7B backpanels, CJC sensors
SCM7B – why are there many bipolar input models, but a lot fewer bipolar output models offered?
The SCM7B series is defined for the process industry which has a preference for unipolar signals on the system / power supply side of the module. In fact , there is a preference for a positive offset above a zero current or voltage output, such as, 4-20mA rather than 0-20mA, 1-5V rather than 0-5V, and 2-10V rather than 0-10V.

Keywords/Phrases: SCM7B bipolar input / bipolar output, SCM7B bipolar output, bipolar output
What is the function of backpanels for signals?
Think of the backpanel as a bidirectional signal transfer device whose direction is determined by the module in a particular channel.
For an input module, the signal is transferred from the field-side screw terminals to the system/power supply-side screw terminals or to a signal access ribbon cable header or D-sub connector.
For an output module it is just the reverse, the signal is transferred from the system/power supply-side screw terminals or from a signal access ribbon cable header or D-sub connector to the field-side screw terminals.

Keywords/Phrases: backpanel, 5B backpanel, 7B backpanel, 8B backpanel, SCMD backpanel
On the 8B51, can I apply the + and – input leads “backwards” to reverse the polarity of the output signal?
This can be done only if the voltage source is floating (isolated); this pertains also to the SCM7B modules.
Better modules for true differential operation for which a floating source is not needed are the DSCA30/31/40/41. Other modules for this type of operation are the SCM5B30/31/40/41 used with an SCMPB07-x with the I/O COM jumpers Jn removed in the channels for which true differential operation is desired. Both the DSCA and the SCM5B outputs can float +/-50V with respect to power supply common.

Keywords/Phrases: 8B51, reverse input leads, true differential
What is the total power consumption of the 7B backpanel?
The total power requirement on the DC power rail is the summation of the power requirement of the individual modules as specified in each module specification. For power budget purposes, multiply the total power requirement you calculated by 1.5 for maximum power needed.

Keywords/Phrases: 7B backpanel, power consumption, power requirement, total power, total power requirement
How do I verify module accuracy?
Long story short, they believe the modules may be less accurate than specified. The biggest error seems to be a low voltage (1-2V), with error decreasing as Vin approaches 10V. The biggest error at low voltage with error decreasing as Vin approaches 10V means that they are calculating error as % of reading. Accuracy of Dataforth modules is specified and calculated as % of Span. The method is the following. Set the test voltage. Apply it to the module input. Measure the voltage at the module input. Calculate the expected module output voltage using the measured input voltage. Measure the output voltage. Calculate the % of Span error by the following formula. Accuracy error % Span = ((Measured Vout – Calculated Vout) / Output Span V ) x 100 This method works for input or output modules. Keywords/Phrases: Module accuracy, accuracy %, accuracy % of Span, Dataforth method for calculating Span accuracy

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