MoTeC Global Forum

Max number of channels is 64, and max rate per channel is 200 samples/second. But is there a rate limit in terms of total bandwidth?
In other words, can I setup 200Hz on all 64 selected channels whithout impact on CPU charge ?
Currently, the CPU charge is about 65%.

And yes, I know memory will be full in less than a minute at that rate

Angelo

Why dont you just give a try and log what happens?

I don't like much the "try and cry" method

Angelo

Hi Angelo,
I log around 50 channels, with different log rate (200hz for front and rear suspensions, other channels with 50hz and other one like engine and air temp with 1hz and my M800 with 1MB logging show only the four last
minutes driving...And this only on a bike....
The only chance is to use a Dash from MoTeC,(for me it's an ADL with 8MB and 50 Inputs/Outputs,Lambda,etc...)
You can also use a M880, with more logging memory....
Cheers
Francois

My question is not related to memory size and logging time, but on bandwith effect on ECU functionality. Admitting I have meg of memory internally in the M800, is the software able to record full speed on all channels.
And obviously, I log some channels at only 1hz, some at 10 and 20hz, and very few at 200hz.

Angelo

Hello,
It can really depend on the overall CPU usage. If you are running lots of functions and lots of logging it is a little different to a few functions and the same amount of logging. Logging will be one of the first things to be cut back if CPU usage gets too high, the priority is running the engine.

Sorry, it's a bit too hard to give an exact answer. We always recommend people log channels at a rate appropriate to thhe channel so I have never really seen anyone try logging 64 channels at 200 Hz.....might try it on the bench here.

MarkMc wrote:Hello,
Logging will be one of the first things to be cut back if CPU usage gets too high, the priority is running the engine.

Thanks, that's the info I was looking for.

Angelo

Polux RSV wrote:

MarkMc wrote:Hello,
Logging will be one of the first things to be cut back if CPU usage gets too high, the priority is running the engine.

Thanks, that's the info I was looking for.

Angelo

Unless you are running a drag car, or a hill climb car where times are finite...
Then maybe a proper logger is needed.

You will hit the CAN bus rate, but if you have more CAN busses, then there is enough room.