Wednesday, September 20, 2017

LoRaWAN Covers the World!

Latest coverage map showing the global reach of network.



Our LoRaWAN Field Test Device from European supplier Adeunis lets you do network validation prior to your solution deployment:

http://www.saelig.com/MFR00007/lorawan-915.htm



The LoRaWAN Field Test Device by ADEUNIS RF is a ready-to-use system which provides connection to any operated network using the LoRaWAN V1.0 protocol. It allows to transmit, receive and instantly view the radio frames on the used network.
Equipped with a large LCD screen, you can check all operating information (GPS coordinates, temperature, battery) and use of the network (uplink, downlink, SF, Packet Error Rate). Its ultra-fast and precise GPS optimizes geolocation operations. 
This Field Test Device is particularly suitable for the validation of applications like sensor networks, asset tracking, smart buildings, metering, security, or M2M.
With a built-in rechargeable battery, to allow many hours of use and can be recharged with any type of mobile phone charger.

Tuesday, September 19, 2017

Automotive Ethernet Compliance: Tests in Detail

http://blog.teledynelecroy.com/2017/09/automotive-ethernet-compliance-tests-in_19.html


Figure 1: Testing transmitter timing master jitter
entails creating a track of TIE measurements
We've begun our deep dive into the subject of Automotive Ethernet compliance testing. In our last post, we covered the first two of seven tests: maximum transmitter output droop and transmitter clock frequency. Let's now look at transmitter timing jitter in master and slave modes.

The test of transmitter timing master jitter uses test mode #2 (see the earlier post on the five test modes). Here, we will examine the RMS jitter of the medium dependent interface's (MDI's) output from the DUT over a period of at least 1 ms. We want to verify that the jitter on the transmitted clock is within the test limit of 50 ps.

To begin, we want to set up a time-interval error (TIE) parameter (see this link for more on TIE measurements). A thumbnail definition for TIE is the difference between actual and expected edge arrival times, which, as it happens, is not dissimilar to the essence of jitter.

Next, we want to create a track of TIE measurements. The track plot gives us insight into how the values change over time. A track plot shows each measured value in the acquisition. Figure 1 shows a zoomed-in view of an acquisition from the DUT's MDI output. We can see 13 TIE measurements plotted in the track that appears in the bottom display grid. Each of these measured values corresponds to a point on the acquisition: one for each edge. In this case, the maximum TIE value is 38 ps at TIE measurement 13. The track reveals that TIE is growing over time.

Checking the RMS value of the track of TIE measurements against the test limit of 50 ps
Figure 2: Checking the RMS value of the track of TIE
measurements against the test limit of 50 ps
Figure 2 shows a full acquisition and the accompanying TIE track. Recalling that we are testing the RMS jitter of the DUT's MDI output, we compare that value to the test limit of 50 ps. In this case, the value is 23.2 ps, well below the test limit.

The test of transmitter timing jitter with the DUT in slave mode calls for direct probing of the DUT's transmit clock (TX_TCLK). Optionally, this test can be approached by using the test mode #3 waveform. Either way, the object is to verify that the jitter on signals received by the slave is within the specified limit of 0.01 UI (150 ps). We will measure the RMS jitter of the slave device's TX_TCLK.

The specification indicates that each device must provide a means to access the transmit clock, but in the real world, this is rarely the case. Most devices are things like an ECU that's totally potted and enclosed. PHY evaluation boards are a different story, but the devices themselves are problematic. And without access to the TX_TCLK, this test cannot be performed. Again, the test mode #3 waveform may be used, but the letter of the specification calls for direct probing of TX_TCLK.

Methodology for this test is very similar to the use of test mode #2 in testing master jitter. We measure TIE, create a track plot of the TIE measurements, determine the RMS jitter of this track, and compare it to the specification's test limit of 150 ps.

Examining the TIE track plots can be revealing in many ways. Referring to the master jitter track of Figure 2, a cursory glance might seem as though there's little change over time but rather only randomness. But looking more closely, one can discern distinct lower-frequency behavior as well as a higher-frequency oscillation riding on top, and some even higher-frequency behavior. If desired, one might measure the frequency of these oscillations with help from cursors. Often, these behaviors can be traced back to something happening with the DUT, or perhaps its power supply.

Monday, September 18, 2017

Test EV Fuel Cells With an Automatic Battery Bank Tester

3kW Electronic Load For Testing Fuel Cells
Simple to use powerful electronic load has constant current/power/voltage/resistance modes


The Model PT04-FC 3kW Electronic Load which has been specifically developed to accommodate the testing of fuel cells as well as low-voltage power supplies, including 24V telecommunications power systems and supplies.  The load is simple and intuitive to operate and is housed in a 4U 19” rack-mount case, with two quiet temperature-controlled fans mounted on the front panel to provide forced air cooling.  Weight has been minimized for easy transportation.  The rugged, reliable design of the PT04-FC provides Constant Current control from 0 to 120A on the 24V range setting and 0 to 60A on the 48V setting, with Constant Power, Constant Resistance, and Constant Voltage also available as standard operational modes, accessible via ATE/remote control.

The Model PT04-FC is also useful as a general-purpose variable electronic load.  It is rated to operate continuously over the specified current and voltage ranges. The standard model offers a differential 0 - 5V input for simple control systems, or can be paralleled for use in larger systems.  
A typical application might consist of an external DC power source to be tested (e.g. an individual battery, or battery pack, a power supply, or a telecomm rectifier) connected to the PT04-FC’s DC power connectors, with the Remote Control Box connected to the load. More than one PT04-FC load can be connected in parallel. 
The standard CP, CR and CV modes are realized by the use of an analog processor circuit between the differential amplifier and load control circuit. This processor measures the DC input voltage to the load, then generates a current demand which gives the required level for the power, resistance or voltage that has been demanded. The Mode control may be changed even while the load is sinking current - the PT04-FC has in-built protection for this. An over temperature alarm monitors the heat-sink temperatures; if a pre-set limit is exceeded then an alarm sound is emitted, the fault output line is activated, and the load current is clamped to 0A until the heat-sink temperature has reduced sufficiently. 
Made by Manatronics, the Australian ISO9001:2008 manufacturer whose load banks are in use all over the world, the PT04-FC 3kW Electronic Load is available now from their USA technical distributor Saelig Company Inc. For detailed specifications, free technical assistance, or additional information, please contact Saelig (585) 385-1750, via email: info@saelig.com,
or by visiting http://www.saelig.com/MFR00095/TSTEQBAT006.htm

Friday, September 15, 2017

Electric Vehicle R&D with Wireless TorqSense

Sevcon in Gateshead, which designs and manufactures high-quality motor controllers and system components for hybrid and electric vehicles, has driven efficiency into its equipment testing regimes by standardizing TorqSense transducers from Sensor Technology of Banbury.

The stakes are high in the race to develop electric and hybrid vehicle technologies, with the winners likely to become leading suppliers to a global market worth literally billions. Sevcon develops drives for electric vehicles such as fork lift trucks, aircraft tow vehicles, golf buggies and scooters. When, in late 2011, it won funding to develop an electric motor controller for trucks, few people saw a high volume future for electric vehicles.
Now, six years later, the whole market is very different. It's truly global and there seems to be no limit to the kind of vehicles that can be 'electrified'. Sevcon's latest GEN5 on-road electric motor controller is the result of a collaborative High Torque Density Switched Reluctance Drive System R&D project, with commercial and academic partners.
IMAGE: Driving efficiency into electric vehicle R&D with wireless torque sensor
Sevcon's Howard Slater says: "In 2011 we focused on bus and truck applications. We've since found that many different vehicles need similar levels of power. That's a huge market that didn't exist when we started. Last year we added 25 new jobs in R&D alone and engineering staff numbers have doubled in less than three years.
As well as developing this cutting-edge technology and winning business in a hyper competitive market, Sevcon has to ensure its internal management systems are reliable, efficient and flexible. One of the ways it has done this is by standardizing Sensor Technology's TorqSense as the core component in its controller test rigs.
In essence, a Sevcon controller is designed to vary the power or torque produced by an electric vehicle's drive motor. In tests a controller is paired with a motor and run for an extensive period, from one hour to 26 weeks, to check the complete speed and performance range over time.
TorqSense is a wireless sensor, which is not physically connected to the test motor's shaft by slip rings. Instead, it monitors the torque via radio waves.
A shaft twists very slightly when it rotates, the amount of deformation being proportional to the torque. TorqSense measures the deformation so that it can calculate torque. To do this two tiny piezoelectric combs are glued to the surface of the shaft at right angles to one another; shaft deformation will expand one comb and compress the other. A radio frequency signal emitted by the TorqSense is reflected back by the combs, with its frequency changed in proportion to the combs' deformation.
"The procedure to set up the TorqSense is very simple and takes only moments," says Mark Ingham of Sensor Technology. "Solutions using other technologies would probably take several hours to set up.
"TorqSense has an enormous overload capacity, which enables it to cope with robust and demanding test cycles, while its digital output signal can be fed straight into a computer program for instant analysis."
The many advantages of TorqSense have led Sevcon to standardise it for all its test rigs throughout the company.
Howard again: "We use TorqSense on four continents. We have a number of test rigs, each dedicated to a particular task. While it would be easy to swap a TorqSense from one rig to another, we in fact don't do that but follow a minimum disturbance routine so that we don't upset rig alignments and can thus quickly and efficiently carry out multi-test regimes.
All of our test staff, from technicians to technical directors, right around the world, are fully trained on TorqSense. This means they can replicate each other's tests and if a person visits another site they instantly understand the local tests and experiments.

More about TorqSense here: http://www.saelig.com/category/MFR00070.htm

Thursday, September 14, 2017

Lowered price! SSA3032X Spectrum Analyzer is now $2595!

The price of the Siglent SSA3032X Spectrum Analyzer - previously $3295 - is now $2595! And the latest firmware upgrade gives free 1 Hz RBW selection! Most competing analyzers only offer 10 Hz!

This represents a major saving for this model.

In addition, on both the SSA30221X AND the SSA3032X the Tracking Generator Option (TG) will now be included at no charge.
Please note: The free TG option is part of a temporary promotion. 

But that is not all….. 


 1 Hz and 3 Hz* Resolution Bandwidth (RBW) positions are now added to both models. The lowest value before was 10 Hz.  Probably no other spectrum analyzer in this price range can do this. Not even close!

https://www.saelig.com/product/ssa3032x.htm

Wednesday, September 13, 2017

What is "RBW" in a Spectrum Analyzer Specs?

National Instruments has a nice answer (http://www.ni.com/white-paper/3983/en/)

1. Resolution Bandwidth

The resolution bandwidth (RBW) determines the fast Fourier transform (FFT) bin size, or the smallest frequency that can be resolved.
The following graphs represent the same signal with varying RBW.







Figure 1. The Same Signal With Different RBW.
The smaller RBW, on the right, has much finer resolution which allows the sidebands to be visible. Finer resolution requires a longer acquisition time. When acquisition time is a factor and the display needs to be updated rapidly or when the modulation bandwidth is wide, a larger RBW can be used. RBW and acquisition time are inversely proportional.  

Tuesday, September 12, 2017

Introducing the RIGOL DS2000E Series Digital Oscilloscope


Uncompromised Debug Solution starting at just $647

If your debug challenge requires advanced analysis capabilities
and instrument performance on an extremely tight budget the DS2000E
allows you to make no compromises

  • 1GSa/sec on all channels provides full 5X oversampling all the time 
  • Free Serial Decode/Trigger supports most of today's common standards
  • 28M Record Length on all channels enables long captures to find elusive problems
  • Vibrant 8 Inch Intensity Graded Display provides easy observation and analysis
  • Waveform Record/Capture, Advanced Math, and 17 trigger types 

Greater performance than the Tek TBS2000 at less then half the price.


Rigol DS2102E 100MHz 2-Ch Digital Oscilloscope