HGL Dragonfly STU with CTU
DISCONNECT THE ANALOG SIGNAL CABLES TO THE HUMMINGBIRD BEFORE CHANGING IP ADDRESSES / POWER CYCLING / REMOVING POWER FROM EITHER THE HUMMINGBIRD OR THE CTU.
FAILURE TO DO SO MAY CAUSE DAMAGE TO THE UNITS.
HGL Dragonfly STU Requirements
The HGL Dragonfly STU Software must be used with a Signal Generator and Multimeter to perform a voltage calibration on Hummingbird and Dragonfly Modules.
Calibrating an acquisition module requires using a Keysight (Agilent) Arbitrary Function Generator (33500B Series) and 6.5 Digit DMM (34465A) with networking capabilities.
Using the Calibration software requires V4 or newer equipment. V4-based equipment added support with CPU firmware version 2.53 / FPGA 5.12. It is not compatible with V2 or V3 Dragonfly systems.
The STU software may be used without the Calibration Test Unit (CTU). However, signals will be loaded as the number of channels being calibrated increases which will lead to problems at high gain levels.
CTU V2 Hardware
The CTU V2 Hardware differs from V1 standard by moving the power, Sig Gen, DMM and ethernet connectors from the top of the unit to back bringing it up to the Hummingbird design standard.
System Wiring
PLEASE NOTE: Disconnect analog signal cables between the Hummingbird and CTU before removing power from the units or changing the IP addresses of a unit. Failing to do so may result in the CTU needing to be repaired.
The Calibration PC must be isolated from other Hawk Systems networks (GREEN or BLACK) because it will rebroadcast messages that will cause the Calibration Software to lock up. Use the HGL Acquisition Terminal to confirm communication with devices or to change device IP Address using the multicast.
- Connect the networks for the Signal Generator and DMM to the Calibration PC on the BLACK network or other spare network.
- Connect the CTU V2 to its own network on the PC
- Connect the power to the CTU V2.
- Before connecting the Outputs on the CTU to the Inputs on the Hummingbird, confirm the Hummingbird is on the correct IP address range, changing the IP of a unit power cycles a unit which can cause damage if CTU cables are attached.
- Connect the outputs of the CTU V2 to the inputs on the Hummingbird/Dragonfly being calibrated.
- Connect the Sig Gen to the DMM and Tee the Output to the BNC Labeled EXT. SIG GEN. 1. on the CTU V2.
- If you are calibrating without the CTU, use a BNC T to connect the CAL BUS to the IRIG on the Hummingbird.
Setup DMM and Signal Generator Networks
- Signal Generator Address=192.168.40.245
- DMM Address=192.168.40.244
HGL Dragonfly STU Preferences
The preferences are defined by an INI file or also accessible via the application GUI. To get to the preferences, the system does need to be working else it can crash when loading, so there are times when the preferences can only be changed from the INI file. The STU Software has different modes of operation depending on what hardware is being calibrated.
The main section of note is Calibration Modes, where the user determines to what level the calibration is done.
- Calibration Only (no adjust) - will run through one calibration but not change any values, this is used to verify a cal on the unit
- Standard (recommended) - will run through a maximum of 3 iterations of calibration, if all channels pass on pass 1 or 2 it will not repeat anything again as there isn't a need.
- Factory - is the most aggressive form of calibration and will run up to 5 iterations if needed.
HGL Dragonfly STU Operation with CTU
Make sure that all devices required for calibration are powered on before starting the HGL Dragonfly STU executable. Use HGL Acquisition Terminal to check IP Address and other settings to confirm communication.
When the software launches, users are presented with simple interface and will need to setup the system.
At the top of the window there are GREEN circles that indicate the presence of each component the STU detects. Numbers in the GREEN circles indicates the quantity for each type. The exception is for DMM which will have a second GREEN circle when two can be detected. Verify that both a Sig Gen and DMM have a GREEN circle.
The new STU software requires the Sig Gen/DMM to have a good calibration date before they will allow the system to calibrate. Most calibration labs fail to update the internal date on these units. To change this date right click on the colored circle corresponding with the unit.
System Setup
Click the "Setup System" text and a window will pop up showing the available devices. The units are separated by type with any CTU units being on the far left, the middle will have any complete Hummingbird listed, and the right column will list all Dragonfly or Hummingbird cards regardless of if they are in a parent device. If the Parent device is configured correctly, simply select the "Unit" to calibrate. If it is a Hummingbird 48, it is necessary to calibrate each half at a time. If it is a Dragonfly module, it will only be on the right hand column.
Please note if a CTU s/n is in ( ) this means it is past its calibration date, please contact HGL for assistance.
Once the devices have been selected, click "Start". If any devices in the Setup need to change, it is necessary to restart the application.
Configuring and Mapping
There will be a pause while the software establishes communications with the different devices, then it will start to configure the CTU a progress bar will be seen. Once done the software will pause briefly again before going into the mapping process. This is done by using a frequency from each output and measuring that on the acquisition device to confirm the channel location. It is possible for this to have a fault on the first iteration (e.g. not detect a connect channel or put it in the wrong location). Click the "Map CTU" button and try again. If this fails, restart the STU software. A successful mapping each channel will have the channel number of the CTU over the channel of the Hummingbird picture with a frequency displayed. A white dot on top of the channel means that channel is active. The CTU V2 is capable of calibrating 32 channels at one time.
Once mapped you should see values in the ovals next to the CTU and DF's that reflect the onboard temperature of each component in the system. It is advised to calibrate once the units have fully come up to temperature ~50 degrees centigrade. If these go blank during the calibration the software has lost communication with the device and it will need to be restarted.
PLEASE DISCONNECT THE SIGNAL CABLES CONNECTED TO THE HUMMINGBIRD BEFORE CHANGING IP ADDRESSES / POWERCYCLING / REMOVING POWER FROM EITHER THE HUMMINGBIRD OR THE CTU. FAILURE TO DO SO MAY CAUSE DAMAGE TO THE UNITS.
Calibrating
Target Cal is used to update the calibration values stored in the Hummingbird and Dragonfly memory. There are two separate amplifier paths in the signal conditioning. One is for standard voltage signals which covers IEPE, Bridges, and Dynamic Strain. The second path is for the charge amplifier. These are calibrated using one of two methods: direct input into the each channel using the CTU or a Signal Generator or routing signals through the Calibration Bus.
Notes regarding using Cal Bus: The cal bus is known for the input signals being attenuated. Also, it is necessary to tee the signal generator input to the IRIG BNC to make the input single ended. Finally, charge calibration cannot be performed using the cal bus.
Performing a full calibration each year is not always required. HGL recommends putting the calibration software in verification mode first and check the results. The frequency calibration should only need to be performed from the factory - if there is significant deviation in the results, contact HGL. Minor frequency response variation of 2-3% is acceptable for daily operation and may be found in the high frequency range. This will vary between conditioning cards as some are only designed for 0- 80 kHz bandwidth.
If the Offset and Gain are outside of the expected values, change the calibration mode to "Standard" and run Offset and Gain in order. Each test will take up to 3 passes to complete (Check and Adjust, Check and adjust, verify).
HGL's Acquisition cards support calibration values for:
- AC / DC Offset values per gain stage
- AC frequency response per gain stage
- AC / DC offset values for a temperature sweep referenced to the internal temperature reading
- Single and Differential charge values per gain stage
- Single and Differential charge frequency response per gain stage
- Noise Floor measurements
- AC / DC Offset Cal Bus adjustment (no specific calibration standard applied as this is just for reference
Before calibrating begins check the calibration mode in the preferences matches the desired outcome. Then select either 'Full Cal' to run a full calibration including Offset, Gain, and Frequency Calibration as well as Charge and Charge Frequency if applicable or select 'Choose' to select which calibrations to run through individually. The software will then go through each of the calibrations.
From here the STU Software will display progress bar at the top with what it is currently doing next to it. Each channel will show active if its being calibrated, along with the gain its currently at and the value it is reading in.
Calibration Results
Navigate to the Calibration Results folder on the C:\HGL Calibration Data. A folder is created for each unit that has been calibrated. Inside is a CSV of the results of each calibration performed.
Open this file with Excel or LibreOffice Calc, a calibration summary is at the top of each csv, showing the serial numbers of all the units in the system during calibration, below is a small table of the 4 highest errors and whether they passed or failed. Further down is the calibration for each channel and each gain with a pass/fail at the far right of the table.
Once all calibrations have been performed and pass a calibration report may be generated using the HGL CTU Report Generator. Use the '...' to navigate to the folder of the desired unit. Click Create PDF Report.
