The ADwin-Gold-III real-time system, combined with the power of ADwinC programming and the flexibility of Python on the user PC, offers a robust solution for high-speed data acquisition, deterministic control, and real-time processing. While ADwinC enables precise real-time code directly on the ADwin hardware, Python serves as a user-friendly interface for configuration, visualization, and data analysis—ideal for both lab and industrial applications.

Key Features:

• Real-time processing with microsecond cycle times and nanosecond precision
• Seamless integration of ADwinC real-time code with Python scripts
• Scalable architecture for control, measurement, and automation tasks

Together, this trio creates a powerful toolkit for engineers, researchers, and developers.

Powerful Real-Time System In A Compact Format

The ADwin-Gold-III is the latest real-time system from the ADwin family. It delivers high computing performance and fast system response in a robust metal enclosure – all at an attractive price point.

Equipped with a wide range of analog and digital interfaces, the system is suitable for a broad spectrum of applications. At its core is a Xilinx Zynq processor with a 1 GHz clock rate, which ensures outstanding real-time performance and processing speed. The connection to the PC is Ethernet-based. Optional expansions include counters, encoder interfaces, serial interfaces, CAN bus, and SSI, making the system highly
adaptable to specific needs.

Typical use cases include:

• Test benches, endurance test stands, and production lines
• Special automation
• HIL – Hardware in the Loop
• EOL – End-of-Line testing
• Simulink models in real-time
• Laboratory setups and quantum physics experiment controls
• DIN-rail mounting in industrial machinery
• Mobile and in-vehicle applications

For multi-device systems, a key advantage is that multiple Gold-III units can operate in parallel, with synchronous acquisition and output across all devices – enabling precise, real-time coordination.

ADwinC – Real-Time Processes, Code Functions & Visual Studio®

Using the C programming language, you can efficiently develop your own real-time processes while also accessing existing functions and algorithms. Functions are available for accessing data, inputs, outputs, and interfaces of the ADwin system. With a single click, the GNU compiler generates an ADwin process that runs on the real-time processor in the ADwin system with absolute precision and predictability, with cycle times from kHz up to 1 MHz.

ADwinC for Visual Studio extends the proven development environment so that you can easily and flexibly write programs for the ADwin-Gold-III in C. In the typical ADwin program structure, you can use the advantages of the C language as usual and add access to the inputs, outputs, counters, and interfaces of the ADwin hardware. At the push of a button, the code is compiled into an ADwin process, which is then transferred to the ADwin system and started.

The ADwin process generated from C runs either in an event-triggered or cyclic mode to handle all time-critical processes with a response time of only a fraction of a microsecond. Processing and output, e.g., of a correction value after a trigger event, is so fast that response times of a few hundred nanoseconds can be guaranteed. The reliably short response time offers so much performance reserve that you can integrate complex calculations into the process.

The ADwinC software package for Visual Studio provides access to all inputs, outputs, and interfaces of the ADwin hardware. Numerous functions are available for this purpose:

• Measuring analog inputs
• Setting analog outputs
• Reading and setting digital inputs/outputs
• Starting, stopping, setting, and reading counters
• Accessing numerous buses and interfaces such as PROFINET, CAN, EtherCAT, etc
• Exchanging data between ADwin processes
• Exchanging data with the PC

ADwinC for Visual Studio supports you in debugging and monitoring running ADwin processes. Visual Studio continuously exchanges data with the running process on the ADwin system. You can display selected process data in the interface and change it online. In addition, configurable ADtools are available to you to monitor key values online, control your real-time processes, and evaluate the process timing.
The built-in timing analyzer provides reliable insight into time behavior and response time of individual processes. Debugging functions allow runtime errors to be intercepted, texts to be output, and self-defined error messages to be triggered in the running real-time process.

Python

Python consistently ranks as one of the most popular programming languages, and it has gained widespread use in the educational community, where it is widely taught as an introductory programming language. Rather than building all functionality into its core, Python was designed to be highly extensible via modules, which makes it particularly suitable for use with the ADwin system as a way to build operator interfaces, visualization tools, and other types of control and analysis applications. A library of functions allows you to directly read and set variables and arrays within programs running in the ADwin system, manage processes, and capture errors.

You can take advantage of Python itself, all the libraries and tools, and with the Qt Designer Standalone software, you can quickly and easily create user interfaces.

For more information on the ADwin-Gold-III, or to find the ideal solution for your application-specific needs, contact a CAS DataLogger Application Specialist at (800) 956-4437 or request more information.

The post High Performance DAQ & Control for Industrial and Scientific Applications appeared first on CAS Dataloggers.

The dataTaker DT8x family of data loggers is extremely flexible, and they allow the measurement of pulse output sensors using several different methods. However, it is not always obvious which method should be used or which might provide the best results. This tech note is intended to provide some background on the techniques we have used to capture data from these sensors.

Sensor Signal Output Types

When choosing which to use, it is essential to know the electrical characteristics of the output pulses that are coming from the sensor. There are 4 common output types:

1. AC voltage output devices: These are not true pulse output sensors but are commonly found in anemometers and gear tooth magnetic pickup sensors. The signal output is an AC sine wave that varies in frequency and amplitude based on speed. In some cases, the voltage output can exceed 90 VAC peak-to-peak.

2. Dry contact devices: These are simple switches. This could be a mechanical switch (e.g., a micro switch or a reed switch) that is periodically closed, for example, by a magnet passing by (like on a door opening switch). In this case, the switch needs some sort of external excitation to generate a signal that can be measured by the data logger. A standard technique is to use a resistor (called a pull-up resistor) with one end connected to a voltage source and the other end connected to one side of the switch; the other side of the switch is connected to the ground of the voltage source.

3. Open collector output devices: These are very common in industrial automation systems and come in two flavors: NPN and PNP. In an NPN output, the emitter of a transistor is connected to the ground, so the output (collector) switches from on to off, effectively creating a series of open and closed connections to the ground as the sensor switches state. A PNP output is the opposite; the emitter is connected to the supply voltage, so the output switches between the open and the power supply voltage as the state changes. Like the dry contact switch, these sensors require an external source to create the pulse waveform. Proximity sensors are one of the most common types of sensors that use open collector outputs.                                           

4. Voltage Output Sensors: These sensors provide a true voltage pulse output. A common type uses TTL standard logic voltage levels; a low (off) is defined as a voltage below 0.8V, and a high (on) is a voltage above 2.0V. The output of these sensors can be fed directly into a digital input or counter circuit of the appropriate type. In industrial systems, you may find voltage outputs that switch between 0 and 24 VDC.

Data Logger Pulse Measurement Methods

The DT8x family of loggers offers 3 ways to measure a pulse output sensor s:

• Frequency measurement using an analog channel
• Low-speed counter using a digital channel
• High-speed counter channels

Each of these has certain advantages and disadvantages that make it more or less suitable for a particular sensor type.

1.  Frequency Measurement

Any of the analog input channels of the data logger can be used to measure the frequency of a repetitive pulse train using the “F” channel type. Internally, the logger has a very accurate time base reference that is used to measure the time between 2 zero crossings of the input waveform.

Figure 1 – Zero Crossing Measurement

By taking the inverse of this time the logger can calculate the frequency of the signal: f=1/(time between zero crossings)

An advantage of using the frequency measurement is that it can accommodate signals up to 50V p-p in series 4 loggers. To improve the reliability of the measurements, it’s best to set the logger to a fixed measurement range using the gain lock command, GLnnn. Also, the default settings allow measurement of a range of frequencies between 33 Hz and 20 kHz making this method suitable for fast pulses.
The main disadvantage of the frequency measurement method is that it relies on the voltage passing through 0.0V which has 2 implications:

a. In the case of a dry contact, open collector, or voltage output sensor, if the voltage does not pass through zero volts, i.e. the sensor switches from 0.5 to +5.0 volts, the frequency measurement will not be reliable. It is possible to work around this by using the reference offset option, 2V, with the F channel type which will apply an offset voltage to the measurement circuit to offset the crossing point to +2.5V.

b. The data logger may time out if the pulse frequency is too low, resulting in an “Under range” reading. The maximum time between zero crossings is 30 milliseconds but can be increased with a sample period as a channel factor option. However, this may affect the data logger’s ability to process other commands.

2. Digital Input Used as Counters

Any of the digital inputs 1D-8D (4D in the case of the DT82) can be used as a low-speed counter. Be aware that the first 4 digital inputs 1D-4D (or 3 inputs 1D-3D in the case of the DT82x) are electrically different from the remaining digital inputs, 5D-8D. The first 4 (3) inputs have a 47k ohm pull-up resistor to the internal 3.3V digital power supply. This makes them especially suitable for use with dry contact switches or NPN open collector sensors. The pull-up resistor will cause the digital input to go to a high voltage when the switch is open or the output transistor is off and will allow the input to go to 0.0V when the switch is closed or the output transistor is turned on. These channels are also compatible with sensors with a TTL output.

The other digital inputs have a 200k ohm pull-down resistor to ground. These inputs are well suited to PNP output sensors or the measurement of sensors that have a voltage output in the on state but are open in the off state. In the absence of an input voltage, the digital input will be 0.0 V or low, and when the sensor switches state, the external voltage from the sensor will cause the input to go high and increment the count. If it’s necessary to use these inputs with a dry contact or NPN output sensor, an external voltage source will be required to pull the input high to allow the data logger to count correctly.

As with the frequency measurement, there are several considerations when using digital inputs as counters.

a. The counters are implemented in software by scanning the digital inputs every 20 milliseconds to see if the state has changed. This means that the width of the pulse must be greater than 20 milliseconds or the logger may not detect the transition between scan times.
b. Based on the scan rate, a maximum measurable pulse frequency, assuming a 50% duty cycle, is about 25 Hz. Pulses of a higher frequency will not be properly counted.
c. When the data logger is asleep, the processor is in a low power state and the channels are not scanned so this method cannot be used to measure pulse counts over longer periods (the default is 30 seconds) when the logger is operating off battery or in a forced sleep mode which causes the logger to go into sleep mode between samples. If the low-speed counters need to be used continuously, the logger should be externally powered and the sleep mode should be disabled by setting parameter P15=2.

3. High-Speed Counter Controls

All of the loggers have 4 dedicated high-speed hardware counter channels (8 in the case of the DT85 S3/S4 models). These channels are capable of counting pulses as fast as 10 kHz. These channels are similar to digital channels 1-4 in that they incorporate a weak pull-up resistor that allows them to be used with dry contact or open collector output sensors as well as TTL output sensors. In addition, channels 1 and 2 can measure low-level signals from millivolt output sensors, such as those with an inductive pickup, using the low threshold (LT) option. This sets the off/on the threshold at <2 mV and >7 mV respectively.

The hardware counters will function if the logger is asleep allowing them to be used over longer sampling intervals however, the maximum count is limited by the width of the counter registers which is 16 bits equivalent to 65536 counts. If more pulses than this occur within the sample interval or if the count is allowed to accumulate over a long period it will overflow and restart back at 0. To prevent a loss of counts, configure the logger to read the high-speed counters frequently enough so that there will never be more than 65536 pulses within any sampling interval. For example, if the average counter input frequency is 100Hz then the DT80 must be programmed to wake at least every 65536/100 seconds (about every 10 minutes).

Also, when used with a dry contact (voltage-free) input where the input is not actively driven to a high state but rather is forced to a high by the internal pull-up resistor, the inputs are effectively filtered to “debounce” the input from contacts in mechanical switches or relays. This limits the maximum count rate to about 500 Hz when used with a voltage-free input.

Flow Meter Example

With all of this in mind let’s consider a common application of a water flow meter. A common turbine flow meter has a simple dry contact output that is triggered when a magnet embedded in one of the turbine blades passes by a reed switch. For this meter, a flow each gallon of flow produces 50 pulses. Therefore, a flow of 200 gallons per minute (GPM) produces 200 * 50 = 10,000 pulses in a one-minute interval or a frequency of 10,000 pulses/60 seconds = 167 pulses/second. For this application, it is necessary to record the flow every 10 seconds so our count for a 10-second interval would be 10 * 167 = 1670 pulse at a 200 GPM flow rate.

Since this sensor has a simple switch output and the pulse frequency is in the range of 100-200Hz, it is easiest to wire it to one of the high-speed counter inputs so let’s use counter 1.

In deTransfer the program would be:

BEGIN”JOB1”

CATTN

‘Spans and polynomial declarations

S1=0,200,0,1670”GPM”

‘Global declarations

RS1S

‘schedule definition

RA(“B:”,ALARMS:OV:100KB,DATA:OV:1MB)10S LOGONA GA

1HSC(R,S1,”Flow”)

END

Here, we have configured the scaling to take into account the 10-second sample interval by multiplying the sensor output by the interval, i.e. a flow rate of 200 GPM will produce 167 pulses/gallon x 10 seconds sample interval = 1670 pulses in the sample interval. Also, we have used the R option in the counter command to reset the count back to 0 after reading the count.

The setup in Delogger would be:

Note the resetting option has been enabled to reset the counter to 0 after each reading. It is not apparent, but the scaling has been adjusted per the previous example.

The setup in dEX would look like this:

The reset counter option has been enabled for this counter to reset the count to 0 after the measurement is made.

The scaling looks like this:

Conclusion

This article has provided an overview of measuring pulse outputs from various sensors using dataTaker DT8x data loggers. By understanding the four common pulse output types—AC voltage, dry contact, open collector (NPN and PNP), and voltage output—users can effectively match their sensors with the appropriate measurement technique. The article detailed three such techniques: frequency measurement, low-speed counting, and high-speed counting, highlighting the advantages and limitations of each. Careful consideration of sensor characteristics, signal frequency, and data logger capabilities is crucial for accurate and reliable data acquisition. We hope this guide helps you select and implement the optimal measure approach for their specific pulse output sensor application.

The post Reading Pulse Output with dataTaker DT8x Data Loggers appeared first on CAS Dataloggers.

IoT smart sensors, called Radionodes, have various and complex functions, making it sometimes difficult to understand.
To understand Radionodes, you need to grasp four things: understanding the sensors, knowledge of different communication methods, familiarity with the cloud, and understanding various industrial scenarios. Those receiving this email are part of the special group I manage, and I will continue to send useful information to ensure you have sufficient understanding.

In this month’s RADIONODE TIPS will cover the instant alarm notification feature supported by the RN17X series and the RN400-T2EX, H2EX products.

Radionode Alarm Instant Sending Function

Generally, alarms sent from Radionode365 are dispatched according to the device’s transmission interval. However, some Radionode products have a feature that allows instant alarm notifications when abnormal data is detected, regardless of the device’s transmission interval. The RN17X series and RN400-T2EX, RN400-H2EX are among these products. These devices are designed to independently detect anomalies within the device by setting a normal range for the sensor, enabling them to send an immediate alarm when abnormal data is identified. Utilizing this instant alarm feature allows for quicker and more efficient responses to deviations.

How to Set Up the RN17X Series

1. Connect the RN17X device to your PC using a USB cable.

2.  Open the Radionode Terminal software, and once the green appears, type “Radionode114” to begin the setup.

(Download Radionode Terminal)

3. When the menu list appears, press the number key 3 and then Enter to access the Buzzer/Siren Setup.

4. In the Buzzer/Siren Setup menu, use Menu A to select the channel for which you want to enable instant alarms. To set an alarm only on Channel 1, press 1 to assign the alarm to CH.1.

5. Use Menus B, C, D, and E in the Buzzer/Siren Setup menu to define the normal range for each sensor from Channel 1 to Channel 4 connected to the RN17X device.

6. To set the normal range for Channel 1, press the B key and then Enter.

7. A prompt will appear to enter the minimum and maximum values for the channel’s normal range. To set the range from -8°C to 25°C, type -8, 25 and press Enter.
8. You will see that the normal range for Channel 1 has been successfully set to -8°C to 25°C.
9. Press Q to exit the setup.

How to Set Up the RN400 Series

1. Enter AP mode on the RN400-T2EX or RN400-H2EX.
   (How to Enter AP Mode)

2. Go to the Measurement menu.

3. In the Dry Contact (Relay and Buzzer Setting) menu at the bottom, set the target channel and normal range for which you want instant alarm notifications.
4. Activate the “BUZZER SOUND ON” option in the Relay & Buzzer menu.
5. Press the REBOOT button to exit AP mode settings.

For further information on Radionode tips, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Application Specialist at (800) 956-4437 or request more information.

The post Radionode Tips: Understanding Instant Alarms appeared first on CAS Dataloggers.

How Does it Work?

It’s like a high-speed camera for data. When a transient event happens like a spike in a power supply voltage, the Expert Transient records it in detail, capturing even tiny fluctuations. This data can then be analyzed to understand the nature of the event, identify the potential source and how to prevent it from happening again.

What Can Expert Transient Be Used For?

The possibilities are endless. Here are a few examples:

• Troubleshooting: Identifying the root cause of equipment failures or performance issues.
• Monitoring: Keeping an eye on critical systems for signs of impending trouble.
• Research: Studying rapid changing processes in fields like science and engineering.

Why Choose the Expert Transient?

It’s reliable, easy to use, and built to last. Plus, it’s designed to work in tough industrial environments. Ready to capture those fleeting moments? The Expert Transient is the tool you need!

Key Features & Benefits:

• High-speed data acquisition: Capture events in the sub-millisecond range.
• Simultaneous measurements: Identify the sequence of events by capturing multiple signals.
• Large storage capacity: Store large amounts of data for detailed analysis.
• Intelligent triggering: Automatically capture events based on predefined conditions.
• Pre and post trigger acquisition: Find out what happened in the moments prior to the event.
• Robust construction: Designed for harsh industrial environments.
• Easy-to-use interface: Configure and operate with minimal training.

Applications:

• Pressure monitoring: Detect and analyze pressure spikes and propagation in pipelines.
• Fault detection: Identify anomalies in machinery and equipment.
• Electrical transient analysis: Study voltage spikes and surges in power systems.
• Sound distribution measurement: Analyze sound propagation and noise levels.
• Vibration analysis: Monitor vibrations in mechanical components.
• Process control: Optimize industrial processes by analyzing transient events.

The Expert Transient is the ideal solution for anyone who needs to capture and analyze transient events.

For more information on the Delphin Expert Transient, or to find the ideal solution for your application-specific needs, contact a CAS DataLoggers Application Specialist at (800) 956-4437 or request more information.

The post Capturing the Fleeting Moments: Delphin Expert Transient appeared first on CAS Dataloggers.

1. Choose a Suitable Data Logger:

• Temperature Range: Ensure the logger accurately measures temperatures within the recommended vaccine range (typically 2°C to 8°C).
• Storage Capacity: Consider the amount of data you need to store and the frequency of readings.
• Remote Access: To monitor temperature remotely, look for a logger with LAN, Wi-Fi, or Bluetooth connectivity. Sometimes, it may be necessary to use a device with Cellular connectivity if none of these is available. Also, consider a device that utilizes cloud-based data storage to allow remote viewing

2. Proper Placement:

• Data Logger Placement: In many cases it is desirable to place the data logger outside the vaccine refrigerator to allow the temperature to be read without opening the door, to optimize wireless connectivity, and to maximize battery life
• Probe Placement: Place the sensor for the data logger in the center of the vaccine refrigerator, away from the door, fan (if present), and any heat sources.
• Secure Attachment: Use a cable tie or adhesive to attach the prober to the shelf securely.
• Thermal Buffer: Consider the use of a thermal buffer such as a glycol bottle or nylon block to help smooth out temperature fluctuations caused by compressor cycling and door opening so the reported temperature more closely mimics the vaccine

3. Configure Settings:

• Sampling Interval: Set the desired frequency of temperature readings (e.g., every hour, every 30 minutes).
• Alarm Settings: Configure the logger to trigger an alarm if the temperature exceeds the recommended range.
• Data Storage: Ensure the logger has sufficient storage capacity to store the desired amount of data.

4. Start Recording:

• Activate the Logger: Turn on the data logger and start recording.
• Verify Functionality: Check the logger’s display or use the accompanying software to confirm that it’s recording data correctly.

5. Monitor and Review Data:

• Regular Checks: Review the recorded temperature data to ensure it’s within the acceptable range.
• Data Analysis: Use the logger’s software or export the data to a spreadsheet program to analyze temperature trends and identify deviations.
• Alarm Notifications: If the logger is configured for alarms, respond promptly to temperature alerts.

6. Data Storage and Reporting:

• Backup Data: Regularly back up the recorded data to prevent loss.
• Reporting: Generate reports to document temperature compliance for regulatory purposes or internal records.

Additional Tips:

• Calibration: Ensure the data logger is calibrated regularly to maintain accuracy.
• Battery Life: Monitor the battery level and replace batteries as needed.
• Remote Monitoring: If using a Wi-Fi, Bluetooth, or cellular-enabled logger, set up remote monitoring to receive alerts and access data from your smartphone or computer.

By following these steps, you can effectively use a data logger to monitor the temperature in your vaccine refrigerator and ensure the safety and efficacy of the vaccines.

For further information on Vaccine Temperature Monitoring, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Application Specialist at (800) 956-4437 or request more information.

The post How To Monitor Temperature In A Vaccine Refrigerator Using A Data Logger appeared first on CAS Dataloggers.

Where Can I Set Up The Alarm?

Radionode365 offers various features to support your data monitoring. The alarm function is one of them and is also a core feature of Radionode365. Therefore, utilizing the alarm function effectively can be considered effective using Radionode365.

This is an example screen of Radionode365. If you look at the left side, you can see that the [Alarm Setup] menu is clicked. In this menu, we can set up and manage alarms. Here, you will see each of the sensor channels you are managing.

If you click the [Add Alarms] button pointed to by the blue arrow in the image, you can configure the detailed settings of the alarm. Additionally, existing alarms can be modified using the [Modify] button.

Now, let’s go ahead and click the [Add Alarms] button.

When you click the [Add Alarms] button, the Data Channel selection window will appear first. Select the channel you want to apply the alarm to, enter the name of the alarm, and then you can proceed to the next step.

The next page is the [Condition] settings. Here, you can make four different settings for the alarm.

If you hover your mouse cursor over the blue Help box, explanations for each setting option will appear. Here are more detailed explanations:

Normal Range (Min~Max): specifies the normal data range where an alarm won’t be triggered. If the monitored data value goes beyond this range, an alarm will be triggered.

Don’t Notify Initially for: prevents alarms from being triggered for a certain period after the data value first deviates from the Normal Range. This is useful to prevent unnecessary alarms in routine situations, such as when opening a refrigerator to retrieve items, causing a temporary rise in internal temperature.

Don’t Notify again for (Snooze): Prevents consecutive duplicate alarms from being triggered for a specific period after an alarm has occurred. This helps to avoid continuous alarms while the person in charge is addressing the issue after the initial alarm trigger.

Don’t Notify Between: Allows you to set a period during which alarms will not be triggered. This can be useful in environments where temperature deviations occur regularly at specific times, such as during scheduled warehouse restocking, to prevent unnecessary repeated alarms.

The next page, the [Notification] tab, allows you to select your preferred alarm methods such as SMS, phone call, email, or simply logging the alarm without notification.

You can also customize the text content of SMS and email alerts, as well as the TTS (Text-to-Speech) content for phone alerts. This enables you to communicate deviations more efficiently and clearly. TTS supports six languages: Korean, English, Japanese, Thai, Vietnamese, and Chinese.

You can view the method for Notification setting introduction through this video:

And the Outgoing Emergency Call Setup through this video:

For further information on Radionode products, or to find the ideal solution for your application-specific needs, contact a CAS DataLoggers Application Specialist at (800) 956-4437 or request more information.

The post How to Set Alarms in Radionode 365 appeared first on CAS Dataloggers.

1. Strain Gauge Measurement 

• What is Strain? Strain is a dimensionless quantity that describes the deformation of a material. It represents the relative change in length (or dimension) due to an applied force and is typically expressed in microstrain (μεm/m).
• How Does a Strain Gauge Work? A strain gauge is a sensor that converts mechanical strain into an electrical signal. It’s typically a thin wire or foil arranged in a grid pattern, bonded to the surface of the object being measured. When the object experiences strain, the length of the wire or foil changes slightly, altering the electrical resistance of the gauge. Strain gauges are available in a variety of configurations to measure the strain along a single axis, or multiple axes or to measure torque/shear.
• Gauge Factor (GF): This is a measure of the gauge’s sensitivity to strain. It’s the ratio of the fractional change in resistance to the fractional change in length (strain). The gauge factor is defined as:

Where R_G is the unloaded resistance of the gauge, ΔR is the change in resistance and ε is the strain. Typically, the gauge factor is approximately 2, and a full-scale value for ε is .001 so the value of ΔR/R will be .002, or for a common 350-ohm strain gauge a change of .7 ohms. To measure a change of 1% you would need to measure a resistance change of .007 ohms in base resistance of 350 ohms or about 20 parts per million.

• Wheatstone Bridge:  Because it is not practical to measure such small changes in resistance directly, strain gauges are often used in a Wheatstone bridge circuit.

In this circuit, the 3 bridge completion resistors R₁, R₂ and R₃ balance the circuit so that the output voltage is zero with no load applied.  Then the output signal can be amplified by the measuring device and very small changes in strain gauge resistance caused by the applied force and measured more easily.

2. Temperature Effects

Strain gauges can be sensitive to temperature changes, which can affect the apparent measured strain. This is because both strain and temperature cause changes in the electrical resistance of the gauge material. Unfortunately, the change in resistance of the gauge material is often nearly the same order of magnitude as the change in resistance due to the applied strain which can make getting accurate strain gauge measurement very difficult in cases where the temperature changes by even a few degrees during the test. There are several ways to address this problem:

a. Using the Wheatstone bridge measurement with bridge completion resistors that match the temperature coefficient of resistivity (TCR) of the strain gauge or using dummy gauges with no applied load as the completion resistors. Since all of the resistors change at the same rate, the bridge will remain balanced (zero output) as the temperature changes.

b. Using temperature-compensated strain gauges. These gauges are designed such that the thermal expansion coefficient of the material/sample is designed to cancel the TCR of the gauge itself. This will minimize any apparent resistance change due solely to temperature.

3. Excitation

The strain gauge bridge circuit requires an electrical current or voltage source for excitation. Also is a ratio-metric device which means that the output voltage changes as the excitation changes. The selection of type of excitation (voltage or current) depends on the specific bridge configuration, the distance between the measurement device and the strain gauge along with the type of wire and the desired measurement characteristics. Factors to consider include:

• Voltage excitation is the easiest to implement and interpret the results. However, because the output voltage is a function of the excitation voltage, it requires a very stable, low-noise voltage source. With long cable runs, the voltage drop in wires can cause measurement errors that must be compensated for. Typical excitation voltages are 5 or 10 VDC but it is important to make sure that the resulting current does not cause self-heating in the strain gauge.
• Current excitation is better when there are long cable runs and it can offer better noise immunity. However, a constant current source can be more complex, and interpreting the results may be more complex.

4. Measurement System

The Wheatstone bridge output voltage is a function of the change in resistance of the strain gauge measurement due to strain. Since the full-scale output of a typical strain gauge is on the order of 3 to 5 mV/V of excitation, with a 10 VDC power supply this would represent 30-50 mV at the maximum recommended strain. The data logger or data acquisition system then amplifies this signal and converts the voltage into a digital value. Depending on the system, it may do additional processing to provide a representation of strain based on the calibration factor (gauge factor and bridge configuration). To improve accuracy, many systems will also sample the excitation voltage since any variation in this value will directly affect the output owing to the ratio-metric nature of the strain gauge discussed in the previous section. Due to the low voltage level of the output signal, averaging or filtering can be used to reduce the noise in the measured value. For example, 60/50 Hz line cycle filtering can be used to remove the effects of EMI from nearby AC power sources.

Conclusion

Strain gauges offer a versatile and sensitive method for measuring mechanical strain. By understanding the principles of gauge operation, the effects of temperature on the measurement, methods of excitation, and the requirements of measurement systems, users can make accurate strain measurements. Careful selection of gauge type, bridge configuration, and data acquisition system is crucial for optimal performance.

The post Introduction to Strain Gauge Measurements appeared first on CAS Dataloggers.

The easiest to use non-encrypted service that we at CAS Dataloggers have found is SMTP2GO. This site offers a free service that provides 1000 free emails a month. When signing up for this service, the website (https://www.smtp2go.com) shows this as a trial, but there is no time limit to this trial, just a limit on the number of emails that can be sent.

All that is required for initial setup is an email and a password. See below for the screenshot:

Once you enter an email and a password, you will get an email with a link to click to verify the email. Once this is done, you’ll be able to log into the account and finish setup which will require you to either use the SMTP password provided or create a new one.

Here are the settings for the dataTaker (or other loggers) to use SMTP2GO:

• SMTP Server: mail.smtp2go.com
• Username: (Email address used to set up SMTP2GO account)
• Password: (Your chosen password. Not the password that is used to log into SMTP2GO)
• Port: 2525 (SMTP2GO offers several ports. 2525 seems to be the most reliable)

Configuration of a dataTaker DT8X Series Logger:

There are 2 pieces of software that can be used to access a dataTaker DT8X series logger. There is a version that runs under Adobe Air called dEX Desktop and one that does not require any Adobe runtimes called dEX 2.0. This setup guide will have screenshots for both software versions, but the basic setup remains the same.

To begin, we will show screenshots of the settings screens where the SMTP server information will be entered.

dEX Desktop

To access this screen, after connecting to the logger, click on “Configure the logger” and then click on the DT8X label at the top of the program column, which will take you to the settings window.

Click on the menu item “Ethernet Email.”

Enter the settings as detailed above in the appropriate text boxes.

Once these changes have been made, you will need to save the program to the logger by clicking on “File” and choosing “Save to Logger”

dEX 2.0

In dEX 2.0, once again, you will need to establish a connection with the dataTaker. Once the connection is established, you will need to click on the “Settings” icon, and then choose the “Communication” tab.

Under the “Communication” tab, select “Ethernet”

As stated above, enter the proper information into the “Email Settings” fields and click “Apply.” Once this is done, the settings have been made on the logger and you can then use email as either an alarm action or to send data.

For further information on using a Non-Encrypted SMTP Server with a dataTaker or other data logger device, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Application Specialist at (800) 956-4437 or request more information.

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This guide will walk you through the steps to properly pair the Bluetooth on your OdaLog L2 or RTx model, with the Bluetooth radio on your Windows PC. There are also quick steps on how to begin using the OdaStat-G software once the Bluetooth is paired.

Step 1. Bring up the Bluetooth & Other Devices window on your Windows PC by typing “Bluetooth” on the taskbar near the bottom left of your screen and clicking the “Bluetooth & Other Devices” system settings link that pops up

Step 2. Once the Bluetooth & Other Devices window pops up, click on “Add Bluetooth or other device” at the very top

Step 3. On the “Add a device” window that pops up, click “Bluetooth”

Step 4. If you see the above screen and your OdaLog logger’s display shows “OFF,” turn the logger on by holding down the button on the top through the “ON” countdown

Step 5. On the logger, press and hold the button until you see ‘BT Pair” on the screen
a. L2 menu order: Status, Start, IRDA, BT, BT Pair
b. RTx menu order: Status, Start, Transmit, BT, BT Pair

Step 6. Watch for the logger to show up in the “Add a device” window on your PC (it may show up as an “Unknown Device” at first). When the Bluetooth radio on the PC communicates with the logger, you’ll see a PIN number on the logger.

Step 7. When you see the logger appear in the pairing window, click on it and the pairing process will complete

Using the OdaStat-G Software After Bluetooth Pairing

Note: this guide assumes the previous installation of the software and the update to allow Bluetooth)

Step 1. Launch OdaStat-G on your PC.

Step 2. In the upper right-hand corner of the software, there is a dropdown to select the communication type. Select “BT Comms – L2/RTx

Step 3. After making this selection, hold down the button on the OdaLog until the display shows “BT” (see section previous for the order of the menu system for each version)

Step 4. When the software sees the logger, the greyed-out buttons will become active. There may also be a message to sync the logger clock with the PC

For further assistance with using Bluetooth with your OdaLog L2 or RTx logger, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Application Specialist at (800) 956-4437 or request more information.

The post Using Bluetooth to Communicate with OdaLog Loggers appeared first on CAS Dataloggers.

With the discontinuation of Adobe Flash support in all of the major web browsers as of January 1, 2021, a number of our existing customers have run into problems using dataTaker data loggers with older versions of the dEX software that relied on Flash.

The good news is that there is a new version of the dEX software that does not use Flash, however, installation can be a bit problematic. Here is a brief guide on installing the new dEX 2.0 software:

Step 1. Download the current version of the dEX 2.0 installer for Windows here.

Step 2. Run the installation program by double-clicking on the .exe file that you downloaded.

Step 3. With normal security settings in Windows, you will get the following warning about running the installer application:

Step 4. At this point, click on the More Info link and a second pop-up window will appear:

Step 5. Click on the Run Anyway button to install the new version of the dEX 2.0 software.

Please be aware that the new version of dEX requires that the logger be running firmware version 9.22 or later. Loggers with older firmware will need to be upgraded. The newer firmware is available here.

Also, the new version of dEX does not use Flash and it is quite different from the previous versions of dEX. You may be able to download your existing program from the logger and import it into the new environment, but the compatibility is limited and some of the features of the previous version may not be supported. The mimics and charts, in particular, are substantially different and will need to be recreated in the new version. You can download a manual for dEX 2.0 here.

For further information on Installing dEX 2.0 for Windows, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Application Specialist at (800) 956-4437 or request more information.

The post Installing the New dEX 2.0 Software on Windows appeared first on CAS Dataloggers.