Weather radar troubleshooting

Below are some tips for troubleshooting the operation of the weather radar, new to the PMDG 777-200LR/F and PMDG 777-300ER as of the Service Pack 1 update and to the PMDG 737NGX as of the SP1d version.
  • Please make sure you have read the weather radar section of the SP1 Supplement in the Introduction and Use manual, as well as the ASN documentation. There is important information about use of the system in both manuals.
Software Requirements:
  • The PMDG 777-200LR/F with Service Pack 1 is required. Download the SP1 (or later) installer here:

    If you purchased on or after the release of SP1 on July 18, 2014, your installer already contains SP1 and the patch version download is not necessary unless it is for a later version than SP1.


    The PMDG 737NGX 800/900 base package with Service Pack 1d

    If you purchased on or after the release of SP1d on March 5, 2015, your installer already contains SP1d and a patch download is not necessary unless it is for a later version than SP1d.
  • The weather radar requires the latest version of Active Sky Next by HiFi Technologies Inc. (hereafter referred to as "ASN"):

    Ensure that you have the latest version of ASN, which is always available for download here:

    The radar does not function with FSX default weather or with any other weather addon besides ASN. To use ASN and the weather radar in FSX Steam Edition or Prepar3D v2.x, you need to have the SP2 version installed.
  • You must have Detailed clouds enabled in the FSX weather options settings. We recommend the settings shown below:

    Not enabling detailed clouds can produce a block pattern on the ND as shown below. This is not because our radar is showing clouds, it's because the detailed precipitation boundaries that ASN injects into FSX get downsampled into very coarse resolution boxes like this when Simple clouds are enabled.

ASN Connect:
  • ASN's AS Connect module dll file (as_btstrp.dll) must be properly installed into FSX's dll.xml file and must be authorized to load into FSX. Normally this should happen automatically the first time you run ASN. FSX itself should be closed before you run ASN for this to occur properly.

    AS Connect's dll.xml should look like this:
    If the dll.xml file is missing this entry or the file is corrupted by formatting errors (a common issue unfortunately), then the radar will not function. If you believe your file is corrupted, submit it to us in a support ticket and we'll fix it for you if necessary.
  • Users have reported to us that they had to run ASN with the right click menu "Run as administrator" command to get the module to install properly. Try this if you're having trouble - most likely this will occur on systems where FSX is installed to the default C:\Program Files (x86) folder instead of it's own custom folder like C:\FSX that's outside of the Windows Vista/7/8 read/write permissions protections placed on the folder.
FSUIPC issues:
  • ASN, much like the 777 itself, uses SimConnect and does not require FSUIPC. Claims that the radar needs FSUIPC installed to work are incorrect - it is not dependent on FSUIPC. Do not try to use any of FSUIPC's weather options while using ASN (smoothing etc) - ASN will override any of them.
  • We have verified that the latest version of FSUIPC (currently 4.939j) does not have any issues with the radar - if you use FSUIPC, we recommend always having the latest version installed as some users have reported that older versions do stop the radar from working via some unknown conflict with it:
  • There is a document in the FSX\Modules\FSUIPC Documents folder called "ASN WX Radar facilities in FSUIPC4.pdf. This document describes FSUIPC4.ini settings and LUA scripts that can be used to create ASN radar displays in other addons that are programmed using FSUIPC instead of SimConnect. (it essentially acts as a frontend/passthrough for SimConnect) This can be problematic because ASN does not support sending data to two different radar addons at once.

    The FSUIPC4.ini (located in FSX\Modules) entries are:

    ASNwxRadarPath =
    ASNwxRadarBitmapPath =

    The LUA script files (located in FSX\Modules) are:


    If you are having issues with the radar and these entries or files are present, trying removing them.
External ASN radar addons:
  • If you are using an external weather radar addon gauge such as the freeware one by Avsim forum user Bryn (which many people installed prior to the release of the 777 SP1) this needs to be removed from your 777's panel.cfg. ASN does not support feeding data to multiple radar gauges at once.
Correlation with ASN's map:
  • Firstly, ASN's map must be in the "Detail" mode for any correlation with the radar in the airplane to be valid. When the ASN map is outside of the Detail mode range, it's showing more generic images that will not necessarily match up with what you see in the sim.

    This is what the detail mode looks like, you should see a checkmark next to the Detail button and the radar imagery should look like this:

    If you see the type of display show below, you are not in detail mode. Detail mode has a maximum range of 90 nm - if you set a larger range than 90, then by definition you are not in detail mode:

  • ASN's map view provides something akin to what's known as a "radar summary" in meteorology terms. What this means is that the strongest precipitation return *regardless of altitude* is being shown. If a particular return is far below your aircraft (while at cruise altitude for instance), you may see it there on the ASN map, but not on the ND in the airplane, depending on the tilt setting you're using. The radar in the airplane is not a summary image - it only shows returns within the altitude range that is being scanned by the current tilt setting.
Misunderstandings about radar:
  • Real life radars show precipitation (rain, hail, ice crystals, etc.), not clouds. Many previous radar implementations in FSX were simply showing cloud positions or making guesses about possible precipitation locations by using cloud locations in conjunction with environmental parameters (temperature, dewpoint etc). We've received tickets from users that show situations like a fair weather cumulus cloud in front of the aircraft with the ND circled in red because the user thinks the cloud should be showing up on the radar. This is not the case - unless there is actual precipitation falling in or from the cloud (according to ASN), you will not see a return on the radar.
  • As mentioned earlier, the tilt setting is important - if precipitation does not lie within the scan cone of the radar beam at the tilt setting you have selected, you will not see anything on the ND.
  • Gain is also important - the automatic gain setting is not going to show a lot of light precipitation (green color on the ND) unless it's turned up manually. Light rain is generally not a threat to a large commercial aircraft, so you'll often only see yellow and red areas that indicate the cores of thunderstorm cells.
Radar brightness on the ND:
  • Make sure that you have the radar/terrain layer brightness turned up/on on the ND - this is controlled by the smaller inner knob on the lighting panel to the lower left of the captain's side PFD or to the lower right of the first officer's side PFD:

If your issue is still not solved by the information in this article, then submit a ticket to us and we'll troubleshoot further with you.

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