Applied Technologies, Inc.
Meteorological Instruments and Weather Systems
Support
Frequently Asked Questions (FAQ)
Welcome to the Frequently Asked Questions section. We have the answer to several problems that have
been encountered when using our meteorological instruments. If the answer to your question is not here,
please send us an email and we'll be happy to answer. We will then include your question in this section.
Send questions to: support11@apptech.com
Click on the question to reveal the answer...
+ Sonic Anemometer (SATI-XXX) has communication (baud rate) problem.
If you have an old SATI ultrasonic anemometer that has not been updated lately - you may still have a user hostile feature (bug) that may be causing you trouble.
The problem:
If 'Output Options' is selected from the Main Menu, the 'Output Options Menu' will come up. The first selection is 'A Baud Rate'. There is no display of the current setting for baud rate and selecting this option does not display the current setting either. It should be obvious to the user what rate he is using to communicate with the sonic, it is the settings for the terminal or terminal emulator that were used to successfully communicate to this point. However, it seems a large number of users select this option to verify the setting. The sonic will respond to this selection with 'New Baud Rate' and wait for input from the user.
The problem occurs when a user does not enter a baud rate at this prompt - ether the current setting or a new valid baud rate must be entered if this option is selected. If nothing is entered, and the Enter or Return key is pressed, a garbage number will be put in non-volatile memory for this setting. The sonic does not make changes to baud rate instantly, we thought that if it did, the user would lose communications and have to reset his terminal settings. So the sonic will not implement this change to baud rate until the next hard reset (power cycle). This adds to the confusion as the user doesn't realize he's made a change.
The Solution:
We have completed the firmware revision that will now eliminate this problem. If you want to be protected from this problem, let us know and you can send your Ultrasonic Anemometer in for this upgrade at no cost. Otherwise, when your sonic is returned to us for other corrections, it will be automatically updated at that time. In the meantime, make sure every user understands the consequences when selecting the 'Baud Rate' option. If this problem does occur, the communication settings can be temporarily set to 9600, E, 7, 1 using the 'Known State' pin on the sonic connector.
Users with a DataPacker can assert 'Known State' using the 'Serial Setup' options menu in the DataPacker and reset the baud rate of the sonic. Users without a DataPacker will need to build or buy a special cable that connects to the 'Known State' pin on the sonic connector. We do not normally connect this pin on a standard cable. The reason we don't connect it is that if the user is using some other setting than 9600, E, 7, 1 and they leave this pin connected but unterminated on the other end, it can unintentionally assert itself and change the communication settings you are working with.
To assert 'Known State', hold this pin low (grounded), while cycling the power to the sonic anemometer. This will temporarily reset the communications settings to 9600, E, 7, 1 and you can communicate with the sonic and reset the baud rate settings that is stored in the non-volatile memory. As soon as the sonic is reset without 'Known State' asserted, it will come up with the communication settings that was placed in memory.
A binary output or an unexpected, valid baud rate setting can look like garbage on the terminal screen. Always try an 'Esc' key (brings up the sonic menus) and a couple possible comm settings before diagnosing this problem and trying 'Know State'.
Please feel free to contact us if you think this has happened to your instrument or you would like assistance with this or any other problems.
+ Is there a program that will allow me to visually monitor the output of the Sonic Anemometer?
Yes, it's called F.R.E.D (fred.zip) available at the bottom of this page. Unzipping the software is required to open the .zip file. Most current windows software has unzipping feature built in, but if not, there are many different programs that will open the .zip file. We suggest you download one from download.com if you do not have software to open a zip file.
+ What programs can I use as a terminal emulator to communicate with the ultrasonic anemometer or DataPacker?
One is HyperTerminal, which comes with Windows Operating System prior to Vista. For some reason it was removed in Vista and Windows7.
Please note: In order to use HyperTerminal, you must turn Flow Control - OFF.
Other programs can be located by searching for terminal emulator software. Some are free, other need to be purchased. Telix is one such program that has been very successful with our customers.
Another is TeraTerm. A link to the Tera Term website is provided below.
Copy and paste this link into your browser to access their website. They provide full support and updates to their product.
+ Can I communicate with an Ultrasonic Anemometer through the DataPacker?
Yes - Access the DataPacker menu by pressing [ESC], select - Serial Setup (A). Select - Change Channel (A) and select the channel your sonic is on, usually channel 1. Select - Serial Pass Through (F). You are now communicating directly to the sonic; another [ESC] will bring up the Sonic Menu. After configuring the sonic, press zero's (0) until your are out of the Sonic Main Menu, then press [CTRL C]. Press zero's (0) until the DataPacker is running again.
+ Technical Note...
DataPacker firmware version 1.42 and earlier has a bug. The sonic data is 95% of an output period behind the analog data. Carl Zeller of the US Forest Service, Ft. Collins, brought this to our attention. We knew that when an analog and a sonic sampling period is initiated with the DataPacker, that at the end of that period the analog data is immediately available and the sonic data has not yet been received. If we output that analog data, it will be one output period ahead of the sonic data which will be received during the next sampling frame and output on the next output cycle. We intended to delay the output of the analog data by one output period so that it would coincide with the sonic data that was sampled at the same time, however, we implemented a delay of one sample period, not an output period. We always sample at least 10 times faster than we output and usually 20 times faster.
Sampling Frequency = 200 Hz
Output Frequency = 10 - 20 Hz
We have an upgrade available at this time. It is best to return the DataPacker to us for the revision, but in some cases we can send a field replacement EEPROM to you to replace yourself.
Please contact us if you feel you need this fix.
TeraTerm Download
Download Fred.zip
We have created simple software to display the output from our ultrasonic anemometer. It's called F.R.E.D
- Fast Response Environmental Display. You can download F.R.E.D here (fred.zip - 51k)
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