Articlets

IST Hardware tech tip 
December, 1999 
Daniel R. Burk 
IST Applications Engineering 
mailto: support@isthq.com

Hello from IST Applications Engineering!

I recently had a conversation with a long-time customer who has several EDR3 systems in his inventory. Sometimes they sit on the shelf for months at a time, but sometimes (like when he called me) he wishes he had a dozen more!

He was lamenting a little about how his recorders were "obsolete", but still served all of his needs. I normally do not try to get into the role of salesman: I'd rather stay immersed in technical applications and troubleshooting. Yet, this time I felt it necessary to try to plug the new software as the solution for his problems. That got me to thinking: What does "obsolete" really mean?  The dictionary refers to obsolete as something that is no longer in use, or is replaced with something newer. It does not refer to age as the sole factor to obsolescence. Were his EDR3 systems, in fact, really obsolete? After pondering this question, I have to say no! The Hitachi-based EDR3 systems are not obsolete. The hardware is still just as useful as ever before. The portion of the system that he had the biggest problems with were in the user interface!

Guess what? The new DynaMax Suite has a completely new user interface called EDR3COM for the Hitachi-based EDR3. EDR3COM has three different methods of user interaction, and each method is incredibly flexible.  As a stand-alone program, users can interact with their system, use quick-start setups for configuring the recorder, and build RCP files for standardized tests. As a launched application, EDR3COM operates as a plug-in for DynaMax. Thus, EDR3COM looks like a feature of DynaMax. As a batch-process program, EDR3COM can perform a preset function with minimal amount of interaction from a user.  EDR3COM, is, in fact, very much state of the art. By purchasing and implementing EDR3COM into his test program, this customer would find himself with a state of the art system with NO additional hardware purchases!

The new software has the ability to craft a streamlined testing program with very little required in the way of operating knowledge: The use of EDR3COM's extensive library of command-line switches means that you can pre-configure a system for a technician. They only need to press a single button on a computer screen to set up the test. In addition, EDR3COM can download data using the same pre-configured method. EDR3COM can even launch the DynaMax analysis program. DynaMax has the ability to use pre-configured analysis scripts that pre-sort the data for you as well. Thus, once a test is created, the execution requires only a minimal amount of effort.

The new user interface has a lot of features that are designed to make your setup as easy and plain as possible. This is beneficial if you are a casual user. EDR3COM, by offering multiple levels of user interaction, lets you choose the level of performance that best suits your needs. You do not need a system that puts you in a straight-jacket; rather, you need a system with high-performance and a high degree of flexibility.  IST systems offer many, many features. Yet, by organizing these features in a thoughtful way, the system becomes easy to use.

If you are using DynaMax DOS (or EDR1S for that matter), consider moving up to the new software. You'll unleash new capabilities for your old hardware.

Tech Tip, December 1999:  Creating a routine test program

Many of our customers have purchased their systems for a specific application. Some customers use them to monitor the transport of satellite systems, whereas others use them to watch for intermittent impacts. In any case, it seems that the user who uses their EDR3 in a different application and configuration each and every time, is rare.

Most customers seem to have their own set of "danger zones" of shock and vibration for their given product. When this phase of a test program is reached, where the product and environment are characterized, the instrumentation phase can become routine. It becomes a matter of monitoring the environment, looking for any outliers that indicate a problem has occurred. The "Danger zone" might be a certain level of acceleration and velocity change (The classic requirements for damage boundary curves), or it might be a certain range of frequencies in a power-spectral-density plot.

In any case, if the testing has stabilized in your test program such that you use the same test parameters for each new test, you can use the new DynaMax Suite to streamline the test program.

Streamlining the setup:

He's making a list, and checking it twice, 
Gonna find out who's naughty or nice, 
Santa Claus is coming, 
        to town!

If you have not done so already, consider creating a checklist for setup. This is the "shopping list" of parts, accessories, and other details that you need to begin the test. This is an important feature if you have more than one person doing the testing, or if you ever need to train someone. Some items to include on your checklist:

Data Recorder, any external accelerometers, with cables
Calibration Certificate for the recorder and any external accelerometers
Mounting hardware (Magnets, adhesive, cable ties, rivet nuts, etcetera)
Communications cable
Windows 95 Computer with installed software. Successful prior communications with recorder verified.
hex wrench for the top cover
new alkaline or lithium batteries
Printout of Recording Control Parameters (RCPs)
Sheet outlining the test procedure including recorder mounting location and orientation
Notepad with pencil for making annotations concerning the installation details.

Be Prepared...

Since you have established a set of parameters that work well for your test, now is the time to put them in an RCP file. Once the RCPs are set up, and resident on the hard drive, you can upload them to the recorder without worrying that the sample rate is set correctly, or the thresholds are set too low. Once created, go ahead and start the recorder with the preconfigured file to make sure that it works. You should ALWAYS pre-test any new setup before the big test.

Keeping it simple:

Once you have an RCP file, you can make up a desktop icon for starting the recorder. The simplest version of the desktop icon is discussed in  Tech Tips for October 99 This link describes a test setup that begins at a specific time, relative to the setup time. What about indeterminate times? Let us consider this scenario:

A aerospace manufacturer wants to monitor the shipment of all new engines with a data recorder. The shipment of the engine is dependent on many factors, and does not occur until a go-ahead from the customer. Therefore, the engine sits, sometimes for several weeks. When the go-ahead is given, it ships as soon as possible. Therefore, a recorder is placed on the engine ahead of time.  Field personnel know about the system and are given minimal training along with a list of procedures for activating the data recorder. If the procedures are kept simple, there is less chance for error. There are two different methods that could be used to make simplify the testing:

1) Equip the technician with a laptop computer with a preconfigured test setup. (This is the preferred method) 
2) Pre-configure the recorder, then place it in standby mode. Have the technician manually cycle the system into active mode via the select switch.

Method 2 is the classic method that has been used successfully for many years. However, there is room for error due to the fact that the top cover must be removed to access the controls. There is also the issue of battery life in the case of the original Hitachi-based EDR3. (EDR3C systems do not have this limitation) If left in STANDBY, the EDR3 will draw current in order to keep the processor alive and the clock ticking. There is also the possibility that the select switch does not get cycled into the correct mode by the operator.

Method 1 requires that the operator only hook up an RS232 cable to the recorder, and double-click on the desktop icon. The systems can be left in the lowest power consumption mode (OFF), and the clock is updated at the time the technician clicks the setup icon.  EDR3COM has several new command-line switches to launch specialized windows, such as customized user documentation. It can also retrieve RCPs for setup verification. Here's some views that graphically show this method in action:

Desktop icon: Setup_Delta_engine



Shortcut path: 
"c:\Program Files\ist\DynaMax\EDR3com.exe" -sendrcps c:\edrdata\delta_setup.rcp -docpage -rcppage

Delta_setup.rcp contains a start time of zero days, zero seconds, and a stop time of T+21 days. When the technician clicks on the icon, they will be prompted to enter some documentation such as shipment number, and name. In addition, a page of control parameters will be presented for review. 



Since the entire process is automated, there is very little room for human error in the procedure.

 


The use of command-line switches is a very powerful feature for EDR3COM. We are striving to make it even easier! Future upgrades to EDR3COM (freely available to DynaMax Suite customers via our web site) will include customized documentation window templates, and automatic desktop icon generators. Stay tuned to this web site for more details.