How to Format intern and extern Memory for Data Logger Firmware

Post by **U.Wilhelm** » Tue 22. Mar 2022, 14:13

The PCAN-Router Pro comes per default with a Data Logger Firmware which could be configured by a simple Text based Config File.
In this Config file you could select which Memory you want to use for save the logged CAN data (*.BTRC files)

Code: Select all

// Drive / memory card selection for saving trace files. Default is EMMC.
// Use   SDC      for SD card
// Use   EMMC     for eMMC device
TRC_DRIVE=EMMC

If you select the external SD Card, you need to format the SD card with FAT32 - see manual

Both memory cards must be formatted with the file system FAT 32
which allows a maximum memory size of 2 TByte. However,
32 GByte is the maximum memory size supported by Windows at
FAT 32. For working with larger SD cards, additional tools are
required.

Here the link to the free available Tool that could be used for format the internal and also the SD cards with FAT 32 (the internal Windows Tools do not support this)
We have made many test with differnt SD cards (up to 1 TByte) and it works perfect - thanks to the developer Tom Thornhill

To give you an overview of the amount of data the logger can record, we have calculate an example for you (thanks to G.Bohlen for the info)

Logging CAN2.0 Data Frames, need always 28 Bytes per Message, independend of the used DLC - this is fix.
Logging a CAN2.0 RTR Frame, need always 20 Bytes per Message - also fix

When logging CAN-FD Traffic, the real count of Data Bytes will be need as storage on the SD card / internal Memory.

Data length: 0-3: 20 Bytes per Message
Data length: 4-7: 24 Bytes per Message
Data length: 8: 28 Bytes per Message
Datal ength: 12: 32 Bytes per Message
Data length: 16: 36 Bytes per Message
Data length: 20: 40 Bytes per Message
Data length: 24: 44 Bytes per Message
Data length: 32: 52 Bytes per Message
Data length: 48: 68 Bytes per Message
Data length: 64: 84 Bytes per Message

For example, with a CAN2.0 frame and a period of 10ms in 8h, this results in a number of 100*60*60*8=2,88 million messages.
These occupy approx. 2,88 million Msgs * 28 bytes/Msg = 80,64 Mbyte.
In addition approx. 1% administrative information results in approx. 81,5Mbyte.

Using a 256MB SD card could store over 9 Mio CAN Frames.
Using a 1GB SD card could store over 35 Mio CAN Frames.
Using a 32GB SD card could store over 1.100 Mio CAN Frames.
Using a 128GB SD card could store over 4.400 Mio CAN Frames.
etc.