FAQ

Q. How do I interpret the binary filenames ?

A. MITesAccelBytes.2006-3-24-11-0-0-0.16

This is a file containing the acceleration signals received at the wireless receiver hooked up to machine placelab16 on date/time 2006/3/24 11:0:0:0 There are six receivers at the placelab on computers 16-21, thus there are six files like the one previously shown. The best acceleration signal is reconstructed from all the receivers and stored in file MITesCompositeBytes.2006-3-24-11-0-0-15. Thus, this is the only file you probably want to read. This file contains the wireless accelerometer signal and all the sensor data from the wireless sensors (e.g. object motion MITes). The file that contains all the one-wire sensor data is OWRawBytes.2006-3-24-11-0-0-0.

Q. I understand that the last two digits of the filename are the receiver ID. Does this mean that there is probably a lot of redundant information in these files ?

A. that is correct

Q. How do I relate the information in PLSensorData.XML to the binary files ?

The information recorded in MITesCompositeBytesxxx and OWRawBytesxxx contains the ID of the sensors activated. You can use this ID to retrieve sensor specific information from PLSensorData.XML such as the sensor description, location, etc.

Q. Several of the "ACCEL" sensors have the same Channel but a different sensor ID. How do I distinguish this in the binary file as only the payload is sent for high SR data ? Is it obvious from the filename ?

A. All the acceleration sensors have a different sensor ID and transmit at different frequencies e.g. 1, 7, 11, etc. If you read the MITesCompositeBytes you do not have to worry about redundant information since it has already being eliminated. This file will contain the acceleration signal for each accelerometer and you can differentiate among the using the sensor ID.