DSCA Series

The upper copper terminal block of the DSCA37 and DSCA47 (pins 6, 7, & 8) are not removable. Those terminal block are directly soldered to the circuit board and contain cold junction compensation (CJC) circuitry. The bottom plastic terminal block (pins 1, 2, 3, & 4) are removable though.

A completion resistor is not required for a DSCA38 strain gauge module in a half-bridge configuration. Half-bridge configuration using the DSCA38 requires two active strain gauges which are denoted as Rg in the block diagrams of the module's datasheet. A quarter-bridge arrangement uses only one active strain gauge and connects to the customer supplied resistor which is denoted as R3 in the quarter-bridge block diagram of the DSCA38's datasheet. This completion resistor is not provided since the resistance value needed will vary depending on the resistance of active strain gauge being used. When using the DSCA38 in a quarter-bridge arrangement, the resistance of R3 should match Rg. Further balancing of the bridge might be needed to offset any small differences between the resistance values of R3 and Rg.

The DSCA32-01 does not come with a dedicated loop power supply that could be used to power a sensor. The DSCA42-01, a 2-wire transmitter interface module could be used instead, since it provides the same input/output range as the DSCA32-01, with the addition of an isolated 24V power supply for powering the 2-wire transmitter/sensor.

Dataforth does not currently offer an equivalent True RMS module for DC coupled inputs, but a two module solution could be implemented depending on the parameters of the DC offset and the AC waveform. Such an implementation was tested with an SCM5B33-03D True RMS Input Module (0-10Vrms input and 0-10VDC output) and an SCM5B31-02 Narrow Bandwidth Voltage Input Module (+/-5V input and +/-5V output). The inputs to these modules were tied in parallel and connected to a waveform generator with a specified VDC offset and VAC waveform within the input limits of the two modules. The outputs of the modules were then connected in series to get a combined output equal to the sum of their individual output voltages. Both modules were mounted on their own SCMPB03 single channel backplanes in order to maintain separate I/O COM lines for the required series connections to be made on the outputs. Alternatively a single SCMPB07 8-channel backplane could have been used since it allows for isolation of each channel's I/O COM line via a provided jumper. Please note that this combined module configuration will result in a small increase in total error since each module's parameters for accuracy are added up. If a two module configuration is not possible for a specific application, a custom version of the SCM5B33 with revised coupling circuitry might be possible depending on the required specifications. Be aware that custom module designs are subject to NRE charges and require a 10pc minimum quantity order.

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.

Two dimensional CAD models can be generated upon customer request. Please contact Customer Service for assistance.

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.

For the DSCA38-02, the +/-30mV range maps to the +/-10V output; -30mV input = -10V output and +30mV input = +10V output. The sensitivity is a specification that refers to the sensitivity of the strain gauges that are fully compatible with the module. If a DSCA38-02 is used with a load cell that has 2mV/V sensitivity, then the module's output is limited to two thirds of the full range (i.e. +/-20mV). This assumes the load cell has a rated excitation voltage of 10V. This reduced output range might be okay depending on the specific use case.

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.

Yes, DSCA modules do come with the screw terminal blocks installed. The screw terminal accessories listed in our catalog are intended as replacements in case a terminal block is damaged or lost.

None of the standard DSCA38 products have a 10Hz bandwidth. However, we do offer some custom products that have 10Hz bandwidth, such as the DSCA38-1348 or the DSCA-1455. Dataforth can also design a custom product with 10Hz bandwidth, as long as the required specifications are reviewed and approved by our Engineering department. Please contact our support team if you are interested in a custom product or have any questions.

The DSCA33 is AC coupled, so it will reject the DC portion of the signal and only measure the AC portion. As long as the signal is within the protection specifications of the module (these can vary depending on the specific model of DSCA33) there will be no issue measuring VAC on top of VDC.

DSCA module screw terminals are rated to wire gage AWG: 28 – 12.

The DSCA30/31 has an input to output isolation of 1500Vrms, meaning that it is possible to measure small potentials on top of a 1500V common mode voltage. This will not damage the module.

All DSCA40 and DSCA30 modules are input protected up to a continuous 240Vrms signal. 12V is well below that rating and will not damage the module.

The overrange capability is approximately 10% of the input range unless otherwise specified in the datasheet. Beyond that level the output will become nonlinear and will clamp either at a reference or power supply rail. Accuracy and linearity are not guaranteed over the minimum and maximum output. The module will not be damaged in any way unless the input exceeds the input protection specification, which is 240Vrms continuous.

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.

Both the TTL and Zero Crossing inputs are single-ended. Both inputs have a 100kOhm input impedance in the power off condition. The TTL input has an input attenuator, so input resistance is approx. 100kOhm. For Zero Crossing input, signals under +/-0.4V don’t clamp the diode so the 100kOhm is in series with the amplifier input which provides high impedance.

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

The DSCA30/31-xx series cannot be modified to have a faster response time. However, the DSCA40/41-xx series is the direct equivalent of the DSCA30/31-xx series, but with a wider bandwidth and faster response time.

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.

A current of 100mA applied to the input of the DSCA32 would be safe. This signal would cause the output to go upscale, but it would not damage the device.

The DSCA33 would still output the RMS of the waveform. However, the DSCA33 may be less accurate due to the crest factor of such a signal.

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.

For models DSCA33-01 through DSCA33-05, the input impedance is 499kOhm with a <100pF capacitor in parallel with the resistor. For the DSCA33-06 and DSCA33-07, the input impedance is 100 milliohms and 25 milliohms respectively.

The DSCA series is completely analog, so the output resolution cannot be expressed in terms of bits as it is not a digital signal. The only thing that would cause any uncertainty/lack of clarity in your output signal would be the output ripple and noise, which is rated at a typical value of 0.025% span RMS as listed in the datasheet.

Although we do not carry signal conditioners that can interface with AC LVDTs, we do have the SCM5B43, 8B43 and DSCA43 which can interface with DC LVDTs.

Our linearized thermocouple modules have a bandwidth of 3-4 Hz in order to reject any induced noise along the sensor line. If a wider bandwidth is needed, a custom module could be designed and manufactured to meet the required specifications. Contact Dataforth at support@dataforth.com to discuss your specific needs.

The DSCA45 accepts TTL signal input across input terminals 6 and 7 (+IN and -IN). A pulse train should be wired across terminals 6 and 7 for proper operation.

Dataforth does not have any custom modules that run on 12VDC power. Most DSCA modules require a minimum power supply voltage of 15VDC while some require a minimum of 19VDC. Both are suitable for use with nominal 24VDC power supplies over the full operating temperature range of -40C to +85C. Dataforth offers a line of accessory power supplies, PWR-PS5RxW, which have been qualified for use with the DSCA product line. https://www.dataforth.com/catalog/pdf/PWR-PS5RxW.pdf

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

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

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.

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

Yes, it is possible. The DSCA33-03 can operate on frequencies from 45Hz to 20kHz.

The DSCA38-12C conforms to EN60079-15 2005. For use in: ATEX 94/9/EC Group II Category 3 (Zone 2)

0.5Nm to 0.6Nm is the recommended range.

0.6Nm is the max recommended torque, but it is still short of damage to the unit.

KEYWORDS/PHRASES: DSCA, screw terminal, DSCA screw terminal, torque

Yes. Replacement terminal blocks are the following.

DSCAX-01 labeled 1 2 3 4.

DSCAX-02 labeled 5 6 7 8.

Keywords/Phrases: DSCA terminal blocks, replacement terminal blocks, DSCA replacement terminal blocks, DSCT terminal blocks, DSCT replacement terminal blocks

To mount the module, do the following.
With the DIN rail mounted horizontally on a vertical panel, hang the hook at the top rear of the module over the top edge of the DIN rail.
Then rotate the module down so the bottom rear corner of the module touches the bottom edge of the DIN rail.
Then push on the bottom front corner of the module until you hear and feel a click. Push and pull the front of the module to ensure it is securely held on the DIN rail.

To remove the module, do the following.
Using a small screwdriver, insert it into the slot on the movable clip (red for DSCA & DSCT) under the bottom rear corner of the module.
Rotate the body of the screwdriver toward the body of the module until the movable clip disengages the bottom edge of the DIN rail and you can rotate the module upward.
Then you can unhook the module from the top edge of the DIN rail.

Keywords/Phrases: DSCA, DSCT, DIN rail module, mounting, removing

No, an external loop power supply is not required in order to provide output loop current. The DSCAxx-xxC and –xxE current output modules have what is known as an active current output. They source the loop current out of their output terminals.

Keywords/Phrases: DSCA, DSCA current loop output, external loop power, external loop supply, external loop power supply

The DSCA and DSCT zero and span adjustments are made using trimpots located under the front panel label and are non-interactive for ease of use. The trimpot screw heads are behind perforated circular knockouts labeled Ø and <->. The screw heads are slotted to accept a narrow flat blade screwdriver. The zero and span adjusters are 25Turn trimpots.

Keywords/Phrases: DSCA zero, DSCA span, DSCT zero, DSCT span, DSCA adjustment, DSCT adjustment, trimpots

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

An external load resistor is required only if the input does not have an internal current to voltage conversion resistor.
Find out the maximum load resistance the output can drive. The maximum load resistance the DSCAxx-xxC, -xxE output can drive is 600 Ohms.
Find out the voltage range the input can accept. Be sure to include the voltage drop at 20mA for the resistance of the length of the lead wires. To calculate the required load resistance, divide the maximum input voltage required by 20mA. The result is the load resistance your application needs to operate properly.

Example: Rin = Vin / 20mA Rin = 10V / 0.02A = 500 Ohms
Lead wire margin allowance example:
Vwire = Rout max x 20mA – Vin Vwire = 600 Ohms x 0.02A – 10V = 12V – 10V = 2V

Keywords/Phrases: DSCA, DSCA current loop output, external load resistor, impedance, ohms

Dataforth modules are designed to be highly stable, thus they do not require re-calibration. DSCA modules can be re-calibrated in the field and they can be re-calibrated by Dataforth. To re-calibrate DSCA modules in the field, download AN801 from the Media Attachments box to the right of the topic main body and follow the instructions. We do offer a re-calibration service. For details, please contact sales by email at sales@dataforth.com or by phone at 1 800 444 7644 press 1 for sales.”