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atmos:citation:instruments:cpi:home

Cloud Particle Imager (CPI)

  • Description: Cloud Particle Imager Model CPI-230
  • Manufacturer: Spec Inc.
  • Serial Number: 003
  • Old NASA Tag Number: 1949624
  • UND Major Equipment Property Tag Number:
  • Weight of the CPI Instrument/Probe: 42.6 lbs
  • Weight of the CPI Power Supply Box: 14.7 lbs
  • Weight of the CPI Computer: 35.8 lbs

CPI Motherboard

  • Form Fator: ATX
  • Socket Type: 775 CPU
  • Slots: Needs on ISA slot for Digital Serial Board (DSB).

Installed a MB930-R mother board in 2011. Mother board failed in January 2014. Order new motherboard from http://www.orbitmicro.com/global/mb930-r-p-12583.html

Problem: CPI Computer Would not Power Up

After a January 2014 lab demonstration, the CPI computer would not power on again.

Trouble Shooting

The power supply in the computer was replaced with a new supply exactly the same as the old supply. The computer would not power up with the new supply. It was determined that the new supply was good and a new mother board order. With the new mother board the computer, would turn on and then off and finally it would not come on. Anothe computer case was borrowed and the mother board and power supply was placed into the other case. The system worked. The system worked in the the CPI computer case; however, the USB port cable had to be connected to the correct location on the motherboard. If the USB port was connected to the trouble shooting location instead of a USB location on the mother board the system would not work.

Cause

Cause of the power on problem was a bad motherboard. This motherboard was also replaced in 2011; hopefully, this one will last longer.

Solution

The motherboard was replaced and the USB cable connected to the correct location on the motherboard. The studs for the motherboard were tighten down and care was taken to use the correctly sized screw to secure the motherboard to the case. All cables were secured together and to the case with wire ties. All fans were checked and cables located to provide good air flow. The cross beam for securing the expansion cards was check and two of the three short holders were found to be broken. We will try to get replacements. The working holder was used to hold down the video card. The new motherboard came with two additional serial ports connect that was installed in a spare slot and connect to the mother board. The additional serial ports will allow additional serial connections to the computer that can be used for data input such as from the NASA REVEAL system. The hard drive cable has secure data connection cables.

The BIOS in the computer had to be set to boot the correct hard drive. The computer will be install in the aircraft and tested with the probe.

Problem: No background or particle images during flight

After several flights and ground tests, the CPI was taken off the plane on August 19th, 2013 due to its inability to take background and poor particle images.

Trouble Shooting

After the CPI was removed from the plane and brought to the lab, it was removed from its casing. Once in the lab, the CPI gave credible background images. After realizing there was a PSD DET_ERROR, as well as Low Laser Power Actual to the 45 degree laser, compressed air was used to blow out all lenses.

Cause

Power cable to the 45 degree laser was loosely connected. Also noticed random changing of threshold setpoint, which may have caused detection/image problems.

Solution

Tightened power cable to the 45 degree laser, eliminating the low values for laswer power actual. For the threshold setpoint, unchecking the box titled “Enable Cycling of Settings” under Settings > Advanced Control Settings stopped the random fluctuations.The “Enable Cycling of Settings” box is found underneath the file save options on the left hand side of Advanced Control Settings.CPI is able to take credible background and particle images when threshold setpoint is set between 250-350. However, images become rare after the threshold is set above 500.

Problem: Can't write files to E drive

On the November 6, 2011 flight, the CPI computer experienced errors indicating that it could not write to the hard drive.

Trouble Shooting

The E hard drive (500 GBytes) is a removal hard data for storing data. The drive was removed and tested. The drive was valid. The CPI computer was removed on November 10.

Cause

The data cable connecting the hard drive to the mother board was very loose at the mother board connections.

Solution

The data cable was reseated. Ways to secure the cable were explored but nothing simple could be figured out. Hopefully, this does not become a recurring problem.

Problem: No House Keeping Data

After the CPI was installed on the aircraft in late 2010, the CPI software does not display valid house keeping parameters. On the House Keeping status window, all parameters up to and including the voltage values have the same digital number. This value changes when the probe is restarted but does not update otherwise, expect if the the serial board test program (??) is running. In the test program display, the second line with the Hex string updates and then several seconds later the CPI House Keeping view window updates.

Trouble Shooting

We tried to change Windows Registry COM setting to all other ports. All COM port settings gave the same results.

A different serial cable between the power distribution box and the CPI computer was tried and gave the same results.

The MA2_DSP card was removed and contacts cleaned. Same results.

All cables and the MA2-DSP card were moved while sampling data. No updates in data when moving cables were observed.

An Oscilloscope was used to look at the Tx lines and clock signals from the CPI probe head. All Tx lines had singles on them. The clock signals looks a little strange with a non flat top. See picture below.

Cause

Not sure of the cause but may of been static electric when either switching out the computer to a new cause or when connecting up the system to the aircraft.

Note that care should always be taken to eliminated static and to ensure things are grounded. When connecting the cables up on the instrument, it is important to first connect all A/C power cables to grounded outlets first before connecting the interface cabling.

Solution

Solution was to send it to SPEC for repairs. They tested the serial board in the computer and found several bad chips. These chips were replaced and things started to work. The system still has an issue with the communication not working the first time and the need for the computer to be rebooted before serial communications works.

Problem: Memory

On October 10, 2008 the computer would not boot and would beep continuously.

Cause

The memory sims in the computer where dirty and not connecting properly.

Solution

The sims where cleaned.

Problem: Key

On October 9, 2008, when the CPI power supply was turned on and the software was used, the software brought up a window saying “Probe Initialization Error.”

Cause

The key authorizing the user to use the software and instrument was not properly connected to computer.

Solution

All the connections between the CPI and the power supply were checked and the A/C power cord was checked with a voltmeter for a proper voltage. SPEC Inc. was called. They suggested to look in the CPI directory and check the cpilog.txt and ritalog.txt files. The ritalog.txt file stated that the user was not authorized. The key to the software needed to be plugged into the printer port. The SPEC Quicklook and SPEC Extractor hasps where inserted into the printer port and the probe still failed to initialize. The hasp labeled “CPI HASP” was removed from the X-TRIG port and attached to the end of the SPEC Quicklook and SPEC Extractor hasps.

  • October 27, 2010 Purchased a new Compac 20 inch computor monitor from Office Max to replace the old defective one per Dave Delene. Will make the proper bracketry to install in the front top rack. Assembly weighs 7.4 lbs.
  • November 26, 2010 Purchased a new chassis and changed out for the CPI computor. Original chassis was 4 inch's to long. All installed and working.
  • March 8, 2011 Installed key board and tray for the CPI. Also installed KVM 8 channel switch box for 3 computors to be ran.
atmos/citation/instruments/cpi/home.txt · Last modified: 2020/01/29 17:25 by 127.0.0.1