CAN Interface + DL1

[Immergewinner]

What is the maximum sampling frequenzy range of the CAN interface to DL1 if all 15 CAN bus channels, to be read?
I need at least 100Hz for all 15 CAN bus channels, is this possible?
Can the DL1 every 15 CAN bus channels with 100Hz and additional 4 analog inputs with 100Hz to Compact Flash?

MArio

[faraday]

Good question.

What component(s) in the logger would limit the sample rate to 100Hz?

One can imagine if it is the processor speed when it has to look after all the internal and external analogue and frequency type channels set at their maxima, a serial stream could soon over tax what headroom is left.

Of course, the ADC might be a limit. Normally 100Hz is plenty, but at times, five or ten times that would be handy.

Where would the greatest additional expense lie in building a DL1 style logger with higher rates on
a) four analogue channels?
b) all external channels?

[Support]

The data storage in the DL1 is done in the following way:

Sample number x
Data 1
Data 2
Data n
Sample number x+1
Data 1
Data 2
Data n

Etc.

Where the data can be any of the defined channels as detailed here:

http://www.race-technology.com/wiki/ind ... taMessages

The sample numbers tell the Analysis software which 0.01s interval the data belongs to. If data comes in more slowly, then 10 samples might pass before new data is present, this isn't a problem. If data comes in at faster than 100Hz, such as from a CAN interface, then multiple samples of data will be stored for the same sample number. In this instance, only one of the samples is used by the Analysis software, the others are ignored.

The biggest problem is not with the hardware (I know that the DL1 can run everything at 200Hz, I've done it before), but the Analysis software. The software prepares all data based on intervals of 0.01s, this will be changing at some point in the future to enable variable sample rates but this hasn't been done yet. When the software is capable of supporting variable rates I will be able to provide hardware that can sample faster.

I hope that makes some sense.

Regards,
Martin

[faraday]

Thanks Martin, sounds promising.

[Dan in Saint Louis]

The data storage in the DL1 is done in the following way:

Martin, is data TRANSFER through the serial port done in a similar fashion? I am still fighting a problem in which all 8 analog inputs RECORD well, but only 3 of them get sent down the 115 kbps serial line to the "Monitor" program in a computer. "Monitor" includes the one from version 6, Monitor and Monitor Lite from version 7. Any idea what could cause that?

Thank you!

[Dan in Saint Louis]

I am still fighting a problem in which all 8 analog inputs RECORD well, but only 3 of them get sent down the 115 kbps serial line to the "Monitor" program in a computer.

Apparently solved by backdating the BIOS (flash) to Mk1/v9. Mk1/v11 was just too hot for it!