Version History

New for SBS

Features added 2.4.3

Features added 2.4.1

Features added 2.3.4

Features added 2.3.3

Features added 2.3.2

Features added 2.3.1

Features added at 2.3

Features added at 2.2

Features added at 2.1

Features added at 2.0


New for SBS

* SBS - As the name implies, the most noticeable introduction to this version of Posfix is the facility to plot SBS-1 transmissions as received by ACARSD Client or JACARS. At the time of writing there appear to be 3 servers with SBS-1 equipment that are passing these on. They are in Sheffield, Zurich and Hungary. These messages give the aircraft's position and height. The position format is slightly unusual, so the first thing Posfix does is reformat the position data into a conventional type. It then plots the position - but only on Map 1. The reason for this is that there are a lot of these plots and they come thick and fast. To avoid so many plots that you can't see any map, I have provided the option to plot SBS-1 plots ONLY on Map one. You can leave this option unchecked and still plot standard ACARS messages on Map 1 - but it might get crowded.

Another consequence of the number of plots, and their concentration, is that Posfix only shows the current position and (if known) the last position of SBS aircraft. This indicates which direction the aircraft is traveling but again will minimize clutter on the map. If an SBS aircraft does not transmit a further message within a set time (default is 10 minutes) it disappears off the map. This assumes that it has landed or is out of range.

You chose whether you want to plot SBS-1 aircraft by checking SBS-1 from the Filters drop-down menu. You can chose to show SBS-1 plots only, and set how long you want to wait for a further message before Posfix deletes it, on the Map Settings menu.

* SBS Aircraft altitude change - Another feature I have added to SBS plots is to colour code the position markers. This makes understanding the local air traffic situation a bit easier.
Yellow - aircraft is descending
Red - aircraft is in level flight (cruising)
Blue - aircraft is climbing
(If you forget which is which this key can be accessed by selecting it on the Maps drop down.)

* Delete Aircraft - You now have the ability to remove (non SBS) aircraft from the map if it is obviously in the wrong place. This can be the result of an incomplete or incorrect message. The aircraft's current position and track are removed from the maps. This option is also on the Maps drop-down menu.

* Re label 'NO REG' Aircraft - Posfix now re-labels plots that don't give Aircraft Reg. Nos, (the No Reg ones) with the Flight Number. This avoids problems when identifying or deleting 'No Reg' aircraft.

New for 2.4.3

* Bugs fixed - There were certain incomplete messages which threw Posfix and caused it to crash when attempting to update the plots. I think I have eradicated all of them. I have also added more fights to plot.

* Clear Maps Daily - I have added the facility to set Posfix to clear all maps of plots at a time that you set in the 'Map Settings'.

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Features introduced at version 2.4.1

* REALTIME TRACKING OF OCEANIC FLIGHTS - The main feature of Posfix 2.4 is that it plots TransOceanic flights in Realtime. Previous versions had plotted these (predominantly Westbound) flights but had shown the aircraft instantly at the end of the Track. With 2.4 the aircraft will not show on maps until it is due to start it's crossing at the appointed Entry Point. From then on it's position is updated every two minutes based on the information contained within the Oceanic Clearance Readback message. For the very rare Eastbound message I have had to assume a start time of 60 mins after the message, as Eastbound messages don't include an Entry Point Time.

* REQPWI - These extended messages are now plotted with a dotted line to signify that they are a forward plot of the aircrafts intended route. I don't have enough information about the aircraft's current position and speed to track these in realtime!!

* Limit Wrong Plots - I have added a filter option to try and prevent route tracks that contain an obviously wrong waypoint. See the filters section below for more details.

* OCA Entry Point Filter- Another way of keeping your maps tidy. See the filters section below for more details.

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Features Introduced at Version 2.34

Posfix 2.3.4 was a small update:

* OTHER DDE - For future DDE sources

* 3 MAPS - so that you can track stuff all over the world using ACARSD Client.

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Features Introduced at Version 2.33

Posfix 2.3.3 added two main features:

* RegFlight - an option to correct wrong aircraft registration numbers or flight numbers in messages See below for more details.
* File Logging - You can now choose to log all messages that are 'Posfixed'

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Features Introduced at Version 2.3.2

Posfix 2.3.2 was another update with some interesting improvements

* FASTER MULTI-PLOTTING - OCA and REQPWIs plot much faster on slower PCs
* DECODE ERROR FILTERING - Posfix can be set to block decode errors. Decode errors are more prevalent using ANAD.
* REPEAT MESSAGE FILTERING - Posfix checks for repeat messages which show up as yellow boxes. The message is not forwarded.
* SQ MESSAGE FILTERING - For those near ground stations.
* MORE AIRLINES PLOTTED - Deltas and Hapag Lloyds added.
* SA MESSAGES EXPANDED - SA messages are COMMS status messages. Posfix now expands the cryptic coded messages to reveal the Aircraft Comms Status.
* FEWER LOOPS - My pet hate. Trans-Atlantic plots that annoyingly loop back to the UK. Also aircraft on return flights with different flight numbers plot separately rather than looping.
* DATABASE TESTER - I have bundled in a simple .exe to test your Posfix databases.

Note. If you are upgrading from a version before 2.31 copy the Posfix.ini file from your C:\WINDOWS directory to your Posfix directory. See below for more details.

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Features Introduced at Version 2.3.1

Posfix 2.3.1 was really just a minor update. It catches a few more aircraft. The main thing is that this version works with the Posfix.ini file located in the Posfix directory. So copy this file from the C:\WINDOWS directory to your Posfix directory. The reason I have switched it to this location is that it avoids problems on some operating systems. See below for more details.

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Features Introduced at Version 2.3

* PC-HFDL INPUT - Posfix can now accept data from Charles Brain's (Commercial version) HF ACARS decoder. See below for more details.

* INPUT DATA FROM SEVERAL DECODERS AT ONCE - Useful if you have more than one scanner and more than one decoder. See below for more details.

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Features introduced at Version 2.2

* UTC CLOCK - Useful for checking message times particularly if local time is not GMT. This will become more useful at a later date!

* MOUSE CLICK INFO - The standard plot shows the Aircraft ID. Left clicking on the plot will reveal the Flight Number (or Flight Numbers if there are overlapping aircraft). Right clicking will reveal Aircraft IDs of any overlapping plots.)

* MAP SAVE - This offers the option to save either Primary or Secondary maps as JPEGS. The default location is the Posfix directory and the default title is the date and UTC Time.

* MAP VIEW - A facility to view archived saved maps within Posfix.

* IMPROVED WAYPOINT DATABASES - I have added every UK waypoint I can find (I have used Nick Locke's Reporting Points Web site for this: http://www.nicklocke.co.uk/Points/PointFullList.asp) I have formatted the Waypoints database in a way that it conflicts as little as possible with similar letters in other parts of the message.

* IMPROVED REFORMATTING - Better OCEANIC plotting, more filtering of duplicate messages, reformatting of REQPWI messages and many more subtle tweaks. There are probably others that I have forgotten.

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Features introduced at version 2.1

* TWO MAPS - You can now use two maps in Posfix. Your Primary Map for the main business and a Secondary Map for the "Wider View" or maybe for North Atlantic tracks as I do. Each map can have its own colour scheme.

* EXPAND WAYPOINTS - I have added the facility to reformat Local Waypoint to coordinates as well as the OCA Waypoints.

* MAX PLOTS - You can now cap the number of plots that Posfix shows on the maps.

* CLEAR MAPS - If you don't set Max Plots and the Maps get too crowded just click this or hit Cntrl+C and all plots are removed and you start again.

* NAT TRACKS - There were several refinements to North Atlantic route plotting. If a route is one of the standard NAT's Posfix will show it's Track Identification Letter to the left of the final Track waypoint. If it is a Random Route this is disabled. Also, if an aircraft includes a current position in a message after one detailing its Trans-Atlantic Route, this plots separately rather than looping back from America or Canada!

* REPEAT MESSAGES - Posfix makes a note of the last 25 messages so that if an aircraft sends a repeat message that has contained multiple positions (OCA or AMDAR) the new one doesn't plot. This helps avoid looping tracks.

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Features added at version 2.0

The big development for V2.0 was the introduction of the map. This plots the aircraft in a less-confusing style than WACARS. Only the last position is labeled. Any previous positions are indicated by a route track.

I also introduced Oceanic Clearance (from UK) reformatting for those who want to see a plane's transatlantic route. It is also useful for those who use the WACARS logs for AirNav. These reformats show in Green. (If anyone from the USA wants to send me Oceanic Clearance messages for Eastbound flights I will configure Posfix to reformat them too).

It featured added an option to Tag messages (Message Posfixed) so that those that have been reformatted can easily be found by searching a log for those words.

I also added two sister adaptations to Posfix (AirFix-A and AirFix-S) for those who use AirNav. These work in the same way as Posfix but don't have their own map-plotting facility. Instead they are designed to output reformatted data directly to Airnav 3.1 instead of using a WACARS log. They also fix some plots that AirNav didn't show but Wacars did. See the AirFix note below for more details. These were subsequently unnecessary and withdrawn from later versions.

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1) If you want to use WACARS with Posfix Amend your WACARS settings so that WACARS gets its DDE input from POSFIX rather than direct from your decoder. Just change the settings in the Wacars.ini file to the following (you will find it in your Windows directory)
note - these settings are different from some earlier versions of Posfix:

Item=Live data

2) Then unpack POSFIX to wherever you like - The default location is C:\Program Files\POSFIX
(I create a short cut for my DDE source, POSFIX, and WACARS in the bottom Task bar next to the Windows 'Start' button.)
Then load them in this order
1) DDE source

If you don't do it in this order POSFIX or WACARS will complain about not having a DDE server! ...Then hey presto! Planes plot that never did before! (assuming of course that they are transmitting position information and you are scanning the right frequencies. I scan 3 simultaneously)

Make sure that your DDE source is outputting data in "Airmaster Mode"

3) When it first launches, POSFIX will ask you to set your DDE source (using the drop down menu). From then on it will remember your settings each time you launch it.

4) Configure your maps using the drop down menu. First select your Primary map using the Browse button. Then set its coordinates. Add a "-" (minus) sign in front of coordinates that are South of the Equator or West of the Greenwich meridian. To help in setting these there are some default coordinates keyed in. These are the ones for the UK map supplied. When you have selected your map you will see a thumbnail of it.

5) Then set the plotting colours you want to use for your Primary Map by double-clicking the relevant coloured box.

6) When your are happy with the settings press "Save Settings".

7) Now repeat the procedure for the Secondary Map. Again the default settings are for the North Atlantic Map supplied. Posfix accepts both .jpgs and .bmps (see more notes on maps below).

8) If you want to limit the maximum number of plots set it using the dropdown menu. The default is no limit.

9) Set Tag Messages if you want to check what has been reformatted.

10) Set Reformat Oceaninics if you want to plot these (see notes below on how it works)

11) If you want to Reformat local waypoints and fixes check Expand Waypoints.

12) Check any other Options and Filters

13) Note that the Posfix message panel is the primary panel. Click its Close (X) box to close the whole programme. Clicking any of the other panels just closes them.

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When using PC-HFDL, HF messages that are in the usual ACARS format are passed on just as they come in (with any position data suitably reformatted). Any HFNPDU PERFORMANCE messages however, are reformatted into a standard ACARS message format that is WACARS and AirNav-friendly. So a message like this in PC-HFDL:

18:15:36 UTC Flight ID = LH8211 LAT 51 0 19 N LON 7 17 18 E

Will be re-output as this:

0ACARS mode: 2 Aircraft reg: .NO-REG
Message label: HF Block id: 0 Msg. no: 0000
Flight id: LH8211
Message content:-

If there is no aircraft Reg. No. in the message Posfix displays the flight number on the map plots. If there is an aircraft Reg. No. in the message it will replace the default NO-REG in the message and on any logs and will show the Flight No. as the aircraft label on plots.

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From version 2.3 Posfix now accepts data from more than one decoder at the same time. This means that if you have more than one scanner you can tune them to different frequencies and get more hits. The combination of decoders is however limited by your soundcard(s). One soundcard will only run one soundcard-based decoder (such as ANAD, ZCARS or PC-HFDL). Some people run two soundcard decoders by fitting an additional soundcard in their PCs. Even with one soundcard though you can still use additional (COM based) decoders such as Airmaster and SkySpy.

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The default Map settings are for the enclosed UK map and the North Atlantic map which are both jpegs.(Note- Posfix also takes .bmps). To see the file to select it make sure you have selected the relevant type in your File Type list box. While on the subject of maps. If you use the "Create a Map" link http://www.aquarius.geomar.de/omc/make_map.html on the WACARS site choose a Equidistant Cylindrical Projection rather than the standard Mercator Projection. It will be much more accurate. Mercator projections increase Latitude spacing's as you go North and South of the Equator whereas the ECP are linear. Cos what Posfix does is convert the Long/Lat information into pixel info and its a lot easier if the distance between say 51N and 52N is the same as between 53N and 54N! Preferably save maps as bmps or jpegs. Also when saving your map make sure that it doesn't include the Long and Lat numbers at the edges in the image or else this will affect position plotting. Another good site is: http://atlas.geo.cornell.edu/webmap/ very pretty maps.

I have created a number of maps covering the UK, France, Holland, Belgium Germany etc which are available on the Posfix web site

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The OCA Waypoints file works like this: It's just like you regular WACARS database files. When you check "Reformat Oceanics" (and only when that is checked) in the Options dropdown menu Posfix does two things:
1) It changes any abbreviated coordinates to full coordinates and
2) Using the new OCA Waypoints database -changes any named North Atlantic waypoints to full coordinates - EXCEPT the last one.

Here's an example - Posfix receives a message like this:

1ACARS mode: E Aircraft reg: .N33103
Message label: B2 Block id: 5 Msg. no: M46A
Flight id: CO0027
Message content:-
/PIKCLYA.OC1/CLA 0932 011118 EGGX
NIBOG 57/20 58/30 58/40

and reformats it to:

1ACARS mode: E Aircraft reg: .N33103
Message label: B2 Block id: 5 Msg. no: M46A
Flight id: CO0027
Message content:-
/PIKCLYA.OC1/CLA 0932 011118 EGGX
N55000W010000 N57000W020000 N58000W030000 N58000W040000
N57000W050000 N55310W057009 N54294W059174

Because the information is now in this format Posfix,WACARS or AirNav will plot it. Note that NIBOG, LOACH and FOXXE have been changed to coordinates. But the line near the end "FM NIBOG/1007 MNTN F340" is not changed to a coordinate. Instead it is changed to "ENTRY POINT TIME /1007 MNTN F340" This prevents the track looping back to the start point! Note. The information in yellow is used to calculate the start time for realtime tracking in Posfix 2.4

At present Posfix recognizes mainly westbound traffic contacting Prestwick (/PIKCLYA.OC1/CLA) because that's all I get in messages. Eastbound messages are pretty rare. If anyone has any others, particularly eastbound clearance messages, let me know and I'll write them in too.

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With this option checked Posfix changes named waypoints into coordinates. Watch out though! This can produce strange tracks! I have added all the local UK (including the March 2003 North Sea changes) and some US waypoints (thanks to Nick Lockes Reporting Points) to the "Waypoints" database file, but you should add your own. Make sure that these waypoint abbreviations don't feature in other words found in messages or they will plot too! That's why I have preceded three letter fixes with a full point. This is the most common way they appear in messages.

Also watch out for messages that include the next three or four wayoints on a route. These will plot. But if the aircraft subsequently updates these in a future message you may get some zig-zagging! From version 2.4 there is also an option to block Oceanic Westbound Oceanic entry points in the Waypoints database by putting a '$' symbol in front of the entry eg.
$ERAKA= N580000W0100000

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It appears that some people think that Posfix works too well. It is plotting so many new aircraft that it is overcrowding even the new simpler maps! This option caps the number of plots shown on the maps. When the limit you have selected is reached new plots show and the oldest plot is cleared (but all tracks, Oceanic and REQPWI plots are maintained).

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Clicking this or pressing Cntr+C clears both maps of all plots and tracks

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Check this if you don't want to be notified by a 'ping' when Posfix reformats a message

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This feature is an adaptation of a programme called AcLog developed by Rene Hess. It is designed to correct incorrect aircraft Reg. Nos. or Flight Nos. contained in messages. These incorrect entries can have a variety of causes. Usually they are because the aircraft has changed ownership and the new carrier has not reset the ACARS box with the new details, Or, in the case of Flight Nos., Posfix will change abbreviated nos. to full (6 character) numbers. All of these can be controlled and updated by editing the RegFlight.wdf database.

This is how it works:
Each line in the RegFlight database has four elements, each separated by semi colons (;). Not all fields need to be filled in but each line of data MUST contain three semi colons. If all the fields were filled in they would contain the following:
Aircraft Reg. No. in message;Correct Aircraft Reg. No.;Flight prefix in message;Correct flight prefix

I have divided the database into common groups to help explain how it works and to keep it tidy. If you take a little time to study it things should become clear. Here are a few examples to explain things:
Example A: Correctly format Reg. No.
..OHLBR;.OH-LBR;; tells Posfix to delete one of the full points and add a dash between the 'O' and 'L'
Example B: Change Reg. No.
.N431UP;.OY-USA;; tells Posfix to replace .N431UP in the message with .OY-USA
Example C: Change a particular aircraft's Flight No.
.HB-IJ;;SR;LX tells Posfix to change the Flight No. prefix of any aircraft beginning .HB-IJ from SR to LX
Example D: Expand abbreviated Flight Nos. to avoid having several variations in your Routes database
;; MH;MH000 (note there are 3 spaces before the MH) Posfix will change Flight nos. like MH3 to MH0003
ExampleE: Recent BA flight abbreviations
;; W;BA0 (note there are 2 spaces before the W) changes Flight nos. like W123 to BA0123
Example F: The Full Monty - use all 4 fields
..IPEKP;.I-PEKP;A8;VA Posfix will add the dash in the Reg. No. and change the Flight No. prefix from A8 to VA

Finally, I must thank Rene Hess for letting me adapt his idea and for his help and suggestions.

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Decode Errors Check this if you want to block some of the common decoding errors
Repeats Check this to avoid Repeat Downlink messages. When Posfix receives a repeat message a yellow box appears and the Flight and Reg. boxes show the relevant aircraft information. The message is not updated in the Message box nor is it forwarded to WACARS or AirNav.
SQ Messages Check this if you don't want to be pestered with SQ messages (applies to those near Ground stations. only). Posfix shows a blue box and no Aircraft or Flight numbers if this is checked.
SBS-1 Check this if you want to decode and plot SBS-1 messages from ACARSD Client or JACARS
Limit Wrong Plots Check this if you want to prevent incorrect waypoints spoilinga neat track. It works by setting maximum permitted distances between waypoints. These settings can be altered in the 'Settings' box.

OCA Entry Point Filter- Another way of keeping your maps tidy. This one works by tagging selected waypoints in the 'Waypoints' database. By adding a '$' symbol immediately in front of a selected waypoint will prevent Posfix plotting it in all but OCA and REQPWI messages. This prevents false plots caused by messages that contain information about when an aircraft is scheduled to be at a particular waypoint. Often this is an Atlantic entry point which the aircraft has not reached yet, so would be a false position. These waypoints will plot in the OCA track (which will show the aircraft position in realtime when it is scheduled to start its Atlantic track). They will also plot in REQPWI routes as they show aircraft's proposed route (with a dotted line).

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Posfix uses standard WACARS .wdf files for the Right and Left Click feature on plots. I have included my own Routes.wdf and Tony Fletchers Aircraft .wdf files with the programme but you might need to add your own local Route info to that particular database or use your own WACARS databases. This (and the Aircraft.wdf) must be in the Posfix directory. You can download the latest WACARS databases from Peter de Winter's excellent site at: http://home.kabelfoon.nl/~pdw/alp/ or Len Nicholson's site http://mysite.freeserve.com/acars

Some tips on adding to your databases. 1) Don't use any commas (,) in databases. 2) In Waypoint databases don't mix Decimal coordinates and Degree/Minutes/Seconds types of coordinates. Preferably use the latter. 3) Beware of entering 3 letter waypoints before a similar 5 letter one. e.g.. put .SHA after SHAPP otherwise .SHAPP in a message will be reformatted as .SHA (SHANNON) because it was the first match Posfix found.

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Messages with the SA Label are very common messages that are transmitted when the aircraft engages or loses Datalink (ACARS) communications via one of its transceivers. Usually VHF, HF or SATCOM. This is a typical message:

2ACARS mode: 2 Aircraft reg: .N775UA
Message label: SA Block id: 4 Msg. no: S27A
Flight id: UA0940
Message content:-

This short message is stating that the aircraft has:
at: 094652
and is communicating by VHF only

Tip: If you are using WACARS with Posfix you might like to put these bits of code in your WACARS Databases:
ESTD=ESTABLISHED in the Airports.wdf database
SA=DATALINK COMMS STATUS in the Modes.wdf database

No, I haven't gone mad - the reason I have suggested you put it in this unlikely place is that all of the other WACARS databases (except Message) relate to the Header part of the message, not the message itself. And if you put it in the Message database you have to repeat it with the appropriate Prefix for every airline! So, I use the Aircraft database for common stuff. WACARS is another reason why I have not got Posfix to reformat these messages with ESTABLISHED in full -because it changes it to ESTAB LISBON ED! Watch out that it doesn't change the SAT or ATC in SATCOM too!

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This decoder offers a further DDE source without having to buy a special piece of decoding hardware. It works using the soundcard just like WACARS does. However, I must confess, that until recently I have had very little success with it. I couldn't get it to decode messages with any consistency (I could with WACARS) and once it was started, I couldn't shut it down!! It crashed my computer!! But, I have recently got a laptop running Windows XP and it works fine on that.

The main problem for DDE purposes, is that ANAD adds a blank line at the beginning of each message and doesn't include the check digits (a 1 or 0 or 0-9) at the start of the text. This throws WACARS because Airmaster and SkySpy do this. It also gets in a mess with some Uplink messages. ANAD is a good decoder but is more prone to Decode Errors than others.

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Unfortunately this decoder by Philip Cummings became discontinued shortly after being released. So I have deleted this option from the server list.

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With the release of AirNav suite 4 Posfix can be used as a DDE source for this software. To activate it - In the ACARS Real-time Interface window of AirNav select "Sources" then "Live Data from other decoder" then "(P) Posfix via DDE". Make sure that you uncheck any other sources that you are running into Posfix or else AirNav will also import the unformatted data from them as well.

If you would like AirNav to display a message explanation text in the Live ACARS Grid for reformatted HFDU PERFORMANCE data, then open A003.dat in your AirNav Suite 4\Data directory and add the following line in the [ML] section: HF=Posfix HFDL position report

If you are using AirNav 3.1 and want to use the latest features in Posfix 2.3 feed Posfix into WACARS and then select "Import from File in Disk" in the "Sources" menu then select the current WACARS log file.AirNav will then read Posfix indirectly through the WACARS file.

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Posfix will accept DDE data from ACARSD or ACARSD Client. To find out more about these decoders go to http://www.acarsd.org

First you need to set up ACARSD to send data. The default DDE output settings for ACARSD are:
Server: SkySpy
Topic: ACARS
Select 'Airmaster Style' in the ACARSD DDE dropdown menu. Make sure that 'no DDE' is unchecked. Then double-click the servers you want to receive data from in the left hand column. When you have done that launch Posfix and in Posfix select SkySpy/ACARSD as your server.
You should then see messages appearing in the 'Messages' box.

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JACARS is based on the ACARSD software and works like ACARSD Client. It gathers data from ACARSD servers around the world. It requires a Java plug-in but is simpler to use that ACARSD Client. It can send data to Posfix via DDE using two different 'footprints'. Check either Airmaster or ANAD as the DDE output in JACARS and set the corresponding DDE server in Posfix. You can download JACARS at: http://leclair.homedns.org/jacars/

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To be honest I hadn't used PC-HFDL very much until I virtually finished the SBS version of Posfix. I had alsways assumed that you needed specialist antennae and receivers. I guess to really do it prpoerly you do. but I was pleasantly suprised to find out that my VHF setup (Yupiteru MVT-7100 fed by loft-mounted discone) was fine for HF ACARS reception. But there are a few subtleties about HF that you don't find with VHF. For instance, the signal needs to be quite precise and it moves about a bit. Therefore you might need to adjust the frequency setting quite a bit as you monitor. I live in the UK so wanted to first try to monitor Shannon. The busiest frequency ssems to be 6532 kHz. Which you key into the Yupi as 6.532. So first you have to set the mode to USB and the Step to 50 Hz (the smallest). I could hear the message bursts but PC-HFDL wasn't decoding anything. However, with a bit of experimenting I found that when I first turned to scanner on I had to adjust the frequency up to around 6.532.6 - or even higher! Then PC-HFDL decodes and tells you how close to the transmitted signal your receiver is. If it shows a ngative offset you need to reduce the frequency setting. If it shows a positive - increase the frequency. The next thing I noticed was that PC-HFDL kept showing negative offsets for a while until (usually) it stabilized somewhat below the 'official' frequency - maybe 6.531.8. Now don't ask me why. I am not that teccie. I can only guess that the receiver or the soundcard needs to warm up.

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In an attempt to 'future-proof' Posfix I have added the facility to set the Server and Topic name of any DDE and then select it as a DDE source. Because Posfix was originally designed to work with WACARS (which has very a strict message-handling format) Posfix was designed to reformat the data from different decoders so that they work all OK in WACARS. So that this will (hopefully) work with future DDE servers, you can select one of three server formats. Choose the one that works best.

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Some of the Databases that Posfix uses are large and inevitably formatting errors creep in when updating them yourself or where introduced by the compiler. This .exe needs to be in the same directory as your databases (i.e. your Posfix directory). Simply type the name of the database you want to test in the top text box (no need to include the suffix .wdf) and press "Test". If the database contains any common errors these will show up in the large window together with a line number to help locate the error. Note. Because of its different format his tester does not work with the RegFlight database.

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VBScript.dll - Run-time Error 13 or 430
When Posfix is installed it should install (or overwrite) a vbscript.ddl file into your Windows\System directory. However, Windows Me 2000 and Windows XP prevent this. The solution is go to Microsoft's Upgrades centre. It will check your computer for any uninstalled upgrades. The one you want is: Security Update, February 14, 2002 (Internet Explorer 6) (there may be a later one now, I haven't checked) - This updates the vbscript.dll to version 5,6,0,7302. Download and install this upgrade and everything should then run OK. (see below for other causes of Error 13). I think this problem has dissapeared with later versions of Windows.

No Messages
If your decoder is registering messages, but none are appearing in Posfix's main panel, this is usually a sign that there is some corrupt data in one of your databases. The most likely cause of this is a line that doesn't have an "=" in it. All lines must either start with a "!" (which denotes a comment line - a line that Posfix doesn't use) r they must contain a"=" separating the text to be reformatted from the text (or coordinate) you want to substitute. You might find that some lines have a"-" instead of a "=". Make sure that there are no blank lines.

Missing .ini File
Very occasionally you may get a message asking you to check whether the Posfix.ini file is in the Windows directory. This problem arises when you try to update the latest version of Posfix from a pre-2.1 version. The solution is to download and install the latest full version. In Windows 2000 this creates a Run Time Error 13 (see next). Posfix version 2.31 (and later) solves this problem.

Windows 2000 and NT
If you got a Run Time Error 13 Type Mismatch message when starting Posfix in Windows 2000 or NT it is again caused by a missing Posfix.ini file. These platforms install the Posfix.ini file in the C:\WINNT directory instead of the C:\WINDOWS directory Posfix is expecting! In the past the solution was to create a directory called WINDOWS in the top level of your C Drive (C:\WINDOWS) and copy the Posfix.ini file to it. With Posfix 2.3.1 (or later) this is unnecessary.

PC-HFDL Not registering
Check that you are using the "Commercial" version. The free demo version doesn't have DDE capability.

Duplicate Plots If you get more than one circle with the same aircraft ID don't worry, it's deliberate. There could be two explanations. It could be a return flight with another Flight Number. Or it could be a REQPWI or OCA plot. Posfix can plot the same aircraft separately from these types of messages as well as a standard position report. It does this to avoid tracks looping back to a current position from a a forward flight plan message. All tracks should actually be overlapping or interlocking

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I have always been a fan of WACARS but was frustrated at seeing many WACARS messages that included obvious position coordinates but which didn't plot on my WACARS map.

WACARS is such a good programme, it is a shame for it to fall short of its potential in this way. It would have been nice to incorporate more position plotting in the programme itself, but despite many efforts I just could not contact Mike Roberts.

So I looked at alternatives.

I originally used a Lowe Airmaster 2000 rather than the soundcard as the front end to WACARS (I now use SkySpy). So I looked firstly at adapting it to reformat the output data before being sent to WACARS. But, for various reasons, this was not possible. So I hit on the idea of creating an intermediary programme.....POSFIX.

POSFIX is a simple programme designed to get a bit more enjoyment out of ACARS scanning and WACARS in particular. POSFIX picks up its data via DDE from Airmaster2000,SkySpy,AirNav ACARS Decoder, Zcars and PC-HFDL, just as WACARS does. It then reformats the data before re-outputting it, again by DDE, to WACARS or AirNav.

When POSFIX receives a message containing position information in a WACARS unfriendly format it beeps, the text box turns blue or green and the message is reformatted. All other messages are passed on unchanged. I have added a few information boxes which also respond to 'hits'. Later I added the ability for Posfix to plot positions on its own maps too. Since then more and more features have been added.

I must apologies if Posfix seems UK orientated. That's because I live here and it's UK skies that I monitor. That's why the Maps are UK and Atlantic. I know other European countries experience similar traffic so you will be able to adapt Posfix easily to your local conditions. Hopefully, those farther afield will also enjoy it. With the advent of Internet-based decoders like ACARSD Client and JACARS you can experience a much heavier stream of messages and monitor traffic all over the world.

Finally, thanks to all those who helped me develop and test Posfix.

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Posfix was developed for my own enjoyment and has proved useful and fun. I hope you have the same enjoyment from it. Posfix is offered as Freeware for anyone who wants to use it. It works fine on my PC and to my knowledge on almost everyone else's who has tried it. However, users do so at their own risk. I hope that you understand that I have to say that to cover myself!

Send any comments/suggestions to Spikey Mikey at its@posfix.co.uk

© Spikey Mikey June 2005