Instrumental Standards

The instrumental standard is based on the EM27/SUN spectrometer that is commercially available through a renowned manufacturer of FTIR spectrometers (Bruker Optics, Ettlingen, Germany) since 2014. In contrast, the existing FTIR networks like TCCON and NDACC are characterized by a larger variety of instrumental setups between the stations, which makes ensuring identical reliable performance more demanding.

EM27/SUN Setup File: EM27SUN.xpm (for Standard COCCON Solar Measuments)

OPUS Macro: RepeatedMeasurements.mtx (for Repeated Solar Measurements)

Reported EM27/SUN Problems

Date of notification: March 25th, 2019.
Date of incident: March 18th, 2019 (1st event) and March 25, 2019 (2nd event)

Instrument's serial number: SN075
Instrument's location: University of Toronto, Canada

Setup description:
Instrument is set up in a Robodome located at the roof top of the physics department building and is controlled remotely. Last set up was March 1st. The instrument was not turned off since.

Opus stopped taking measurements and froze. The following OPUS error occured:
"Optical bench is in STANDBY mode". See Fig.1 and Fig.2.

Temporary Solution:
Restart the instrument (turn off and on the EM27/SUN).

Date of notification: from February 2nd, 2021, onwards
Date of incident: from February 2nd, 2012, onwards

Instrument's serial number: NA
Instrument's location: NA

Setup description: Notebook running Windows® 10 OS and EM27SUN using VRmagic Camera.

Windows® 10 and the CamTracker (this collection of advises have been compiled by Jochen Gross, KIT)

Temporary Solutions:

  • Windows® Updates
    Did the problem appear immediately after a (possibly silent) Windows® update. Try rebooting (eventually several times)!
  • USB Driver(s)
    Most of the problems we experienced had to do with missing, faulty or misbehaving buggy USB drivers (not the camera drivers!), especially when using "new" USB3 equipment. Try to get the driver that fits best to your USB chipset and Windows® version. You should get them from the support area of the computer's or motherboard's maker. Or even more up-to-date directly from the chip(set) manufacturer. To find out the model, have a look at Windows®' device manager. Even with yet unknown ports/chipsets (showing a yellow exclamation mark) go to "properties", "details", and finally to "hardware-IDs". Here you'll find the vendor-ID and device-ID, e.g. "[...]VEN_8086&DEV_9D2F[...]". Use this information to search the internet for the correct driver and/or firmware package. Beware, do not download anything from anywhere but the manufacturer's site.
  • USB Hardware
    Also USB (especially USB3) cables are very prone to fail. Have you tried another one (e.g. a shorter one)? Long cables may suddenly stop working if you run them alongside other energized cables.
  • EM27 USB Socket
    There is a "hardware bug" at the outer USB socket at the EM27. If this has not been fixed yet, the inner part may slide away backwards some millimeters. If you then use the provided on-screwable USB plug you will not get solid contact anymore.
  • CamTracker Software
    There is one screw you can turn: the pixel clock. If you have too many disruptions in the transfer (that is when you get blue screens) a lower pixel clock will reduce the amount of data transferred in the same time and be therefore more stable. (If you have installed the VRmagic DevKit of the camera, you can test the camera and detect dropping frames with the "CamLab" program.) The pixel clock is changed in CamTracker's internal configuration file. Play with it. Keep in mind: Due to the principle of real time video stream transmission over USB you cannot guarantee the correct transfer of "_every_ frame". At least not in this USB mode. But normally some rare blue screens are no problem for the CamTracker. It will log a warning and go on with the next image it can get. Apart from that there was only one little fix for CamTracker regarding the graphical user interface if you use the "high dpi" settings of Windows® 10, i.e. if you use a scaling (for fonts, apps etc) other than 100%. So there were no changes in the software on the USB side. Any recent version should do.
  • The Camera's Driver
    It has not been updated for a long time (and it won't in the future), and if everything worked well in the past, I am pretty sure you already have the freshest driver (v1.0.9.8) installed. The vrmusbcam2.dll should be v3.5.0.0
    Caution: If you have played with the DevKit of VRM (you know what this is as you have installed it), you have to be sure that you use the 32-bit version! The type (32bit or 64bit) is not related to the operating system but the software that will use the driver (CamTracker.exe is a 32bit executable).
  • The Camera
    Another idea: the camera is just broken? Did you try with another PC and/or OS to get a stable video stream? There is also a slight chance that you own a camera with an old firmware version. You can check the firmware version with the CamLab tool from the DevKit. It should read "22.10". In case it does not, you can get a firmware update tool from <>. But only start an update with a surely fine working USB environment. Here we've come round in a circle.