I performed first flight in my home built aircraft last week and was looking forward to viewing the flight and engine data however, no such file existed on the sd card once uploaded to my pc. I thought it would automatically record this at all times and when sd card is full would write over the oldest files. Does anyone know what I need to do to have the data record every flight or even if I have to tell it to every flight how would I do this?
My system is explorer lite.
Cheers
Murray
Flight and engine data (Black box info)
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Re: Flight and engine data (Black box info)
The EFIS records this data only when a flight is active. Ensure you have setup your EFIS so it properly detects start and end of a flight or if you use manual mode you start and end the flight in the action menu. You know that a flight is active if you look at the flight timer on the screen and it is flashing (assuming you are using standard screens or have a custom screen that includes the flight timer).
The EFIS automatically records to an internal memory chip. This tends to hold about the last two hours of flight. You can extract this data to an SD using the relevant function in the common tasks menu.
You can also record to an external SD card in parallel at the same time. The card must be formatted FAT32 and you must prepare a recording file called iEFIS.REC. This is fixed size file and the size determines how much data it can record. You can use 1MByte = 1 hour as a rough estimate. It depends a bit of what the EFIS records and that is dependent on your setup - for example it makes a difference if you have one or four engines to monitor.
You will find functions to enable the external recording in the Flight data recording setup menu as well as functions to create the recording file.
You can create the file by any means (for example on a PC). It must be a file filled with zeros to start and the file size must be evenly dividable by 512 (the size of a disk sector). If you create a file that is say 1GByte in size - it will hold roughly 1000 hours. The recording starts at the start of the file and proceeds to the end in chunks of 512 bytes (the logical size of a chunk of data that can be written in one transaction). If the end of the file is reached it wraps back to the start. Each sector contains information (the first 4 bytes) of the date and time of that data. When the system first starts it will look for that file and scan it to find the oldest sector (or a zero one) so it knows where to continue the recording from.
If you have everything enabled and setup you will see a pop up in blue just at take-off telling you that recording has started. If it is setup but cannot find the recording file it will give a red message to that effect.
In order to read the data you use the iEFIS Black box flight data viewer application. This first splits the recording file into individual flights (with filename based on start date and time) when you import the raw recording file. After that you can view the individual flights. As there can be a lot of data items - you select which ones you want to view in the graph - I usually start with altitude as that is a nice reference over the flight and then add other items I am interested in. You can also zoom into a segment if the flight is long.
You can export the data in some formats (for example to import into excel) and you can also export a KML file of the flight profile in 3D which you can view in Google Earth superimposed over terrain. This is quite useful as well.
Finally the reason we use a fixed sized recording file is SD card wear - these cards use Flash memory which has limited amount of write cycles. if you start a zero length file and grow it it requires an update to the directory holding the file information for every single write apart from changes to the file system structure records. This tends to destroy the SD card - sometimes fairly quickly. The cards have error detection and correction algorithms built in and will swap out bad sectors with new ones (there are spare sectors - that's why if you buy a 16GByte card it only shows 14Gbytes or so when you view the disk size - some sectors are bad from new and have been removed during production.
Anyway - by doing it our way there is effectively zero wear to the card - the only danger remaining that during a sector swap it is not possible to recover the original sector or the swap fails due to unexpected card removal etc.
I hope this makes it clear...
The EFIS automatically records to an internal memory chip. This tends to hold about the last two hours of flight. You can extract this data to an SD using the relevant function in the common tasks menu.
You can also record to an external SD card in parallel at the same time. The card must be formatted FAT32 and you must prepare a recording file called iEFIS.REC. This is fixed size file and the size determines how much data it can record. You can use 1MByte = 1 hour as a rough estimate. It depends a bit of what the EFIS records and that is dependent on your setup - for example it makes a difference if you have one or four engines to monitor.
You will find functions to enable the external recording in the Flight data recording setup menu as well as functions to create the recording file.
You can create the file by any means (for example on a PC). It must be a file filled with zeros to start and the file size must be evenly dividable by 512 (the size of a disk sector). If you create a file that is say 1GByte in size - it will hold roughly 1000 hours. The recording starts at the start of the file and proceeds to the end in chunks of 512 bytes (the logical size of a chunk of data that can be written in one transaction). If the end of the file is reached it wraps back to the start. Each sector contains information (the first 4 bytes) of the date and time of that data. When the system first starts it will look for that file and scan it to find the oldest sector (or a zero one) so it knows where to continue the recording from.
If you have everything enabled and setup you will see a pop up in blue just at take-off telling you that recording has started. If it is setup but cannot find the recording file it will give a red message to that effect.
In order to read the data you use the iEFIS Black box flight data viewer application. This first splits the recording file into individual flights (with filename based on start date and time) when you import the raw recording file. After that you can view the individual flights. As there can be a lot of data items - you select which ones you want to view in the graph - I usually start with altitude as that is a nice reference over the flight and then add other items I am interested in. You can also zoom into a segment if the flight is long.
You can export the data in some formats (for example to import into excel) and you can also export a KML file of the flight profile in 3D which you can view in Google Earth superimposed over terrain. This is quite useful as well.
Finally the reason we use a fixed sized recording file is SD card wear - these cards use Flash memory which has limited amount of write cycles. if you start a zero length file and grow it it requires an update to the directory holding the file information for every single write apart from changes to the file system structure records. This tends to destroy the SD card - sometimes fairly quickly. The cards have error detection and correction algorithms built in and will swap out bad sectors with new ones (there are spare sectors - that's why if you buy a 16GByte card it only shows 14Gbytes or so when you view the disk size - some sectors are bad from new and have been removed during production.
Anyway - by doing it our way there is effectively zero wear to the card - the only danger remaining that during a sector swap it is not possible to recover the original sector or the swap fails due to unexpected card removal etc.
I hope this makes it clear...
Re: Flight and engine data (Black box info)
Thanks Rainier,
It turned out to be the SD card I was using wasn't formatted FAT32. Worked fine once I used the correct format.
It turned out to be the SD card I was using wasn't formatted FAT32. Worked fine once I used the correct format.