about the ‘sid’ file format

Q. What is SID?

A. It’s a standard file format that every data logging manufacturer is encouraged to support.

The results of data logging experiments can be better shared in the ‘SID’ format. This is a file format that works across different manufacturers software. We should be able to ‘Open’ these files in our data logging program. Look in the File menu of your software for a reference to ‘SID’ in the ‘Open’ or ‘Import SID’ dialogues.

If you can’t get your data logging software to do this, you can open a spreadsheet program, go to ‘File / Open’ and change the ‘Files of Type’ box to read All Files (*.*). Then search for the place where the Internet program saves things. You will end up looking at a fairly big table of data with readings in columns. You can then use the data to draw a scattergraph or do calculations.

You can also load a SID file into your word processor program. If you highlight the data you can turn it into a table of text. One of the difficulties with using anything other than a data logging program to open a SID file is that data logging produces lots of readings. In turn that means that your table will be about 600 rows long. Some data logging programs recognise this point and let you save a subset of the results, for example, they’ll let you save say, one in five readings.

Occasionally your spreadsheet program will fail to recognise that the file is ‘comma separated text’ (see below). In this case, look for a command in the ‘File / Open’ dialogue box that tells the program to treat the file as comma separated text.

Why have a SID file format?

Different computer programs save data in proprietary formats. Each program can read its own format, but not any other and the result is the mess called ‘IT’. Years ago the UK people who wrote data logging software got together to decide on a format that everybody’s software could understand. Amazingly they made a decision, and this file format called SID. Some manufacturers couldn’t see the point of it.

The experiment results published here were obtained using various data logging programs. You should be able to get these results into whatever data logging program you use. That’s provided that the people who wrote your program know about SID.

About the SID format – technical specs

Software developers wishing to support the SID format can download the SID technical specification (Acrobat)

The SID format is a form of ‘comma separated value’ file. Sensor readings are placed on a single line and if several sensors were used at the same time their readings sit next to each other separated by commas. Here’s a portion of a SID file just to make that clearer. Note that the first part of the file is called the header. A data logging program will be able to translate the header and display the appropriate axis scales:

%%identifier,SID
%%datasize,155,4
%%title,Weather 27 April
%%fieldname,1,Time
%%fieldunits,1,seconds
%%fieldname,2,Light
%%fieldunits,2,%
%%maxmin,2,100.0,0.0
%%fieldname,3,Temperature
%%fieldunits,3,celsius
%%maxmin,3,50.0,0.0
%%fieldname,4,Temperature
%%fieldunits,4,celsius
%%maxmin,4,50.0,0.0
%%interval,512
0,44.4,18.1,11.2
512,0.9,17.7,8.2
1024,0.8,17.4,8.4
1536,0.9,17.2,8.5
2048,0.8,17.0,8.5
2560,0.7,16.8,8.5
Then more readings…