Improving Data Logging Speeds

[S3Rich]

As per title

i have the $100 registerd version of vcds and an ebay joby usb lead and drivers it works brill no problem with vcds or lemmiwinks.the only downfall is the latency says it poor im no computer whizz but im not a novice,obvioulsy with the full cable i should get better data logging over 3 groups as at the mo its dropping to 0.8 which is pretty slow,is it purely the cable or do you need quite powerfull laptop for logging multiple groups?the laptop is red hot when running vc scope and logging etc could it be my processor speed is not capable it only a celeron M i think.

let me know your thoughts

 

[NHN]

Celeron M is fairly old tbh mate, should be ok though if its only this in use on that machine, but you do have turbo mode but this runs one block at a time iirc not 3, give RT a shout on support@ross-tech.com & if they advise the full monty is required to improve this, then give me a shout & I can supply this for you.

 

[bearthebruce]

It is not the laptop that is limiting the speed. It is the controllers in the vehicle that limit the rate of speed. 0.8 for 3 groups (12 values) is pretty normal on older cars. If there is a Turbo mode, and I am not certain VCDS-Lite supports it as I don't see anything about it in the online manual, you might get a little faster performance by selecting Turbo.

Speaking of that manual, sample rate info states:

Sample Rate: We can get just over 4.0 samples per second from our '97 VR6 ECU (single group) with the most aggressive protocol-timing settings. This ECU runs at 9600 baud. Most newer ECU's run at 10400 and should give proportionately more. Naturally, if two groups are being displayed simultaneously, the sample rate drops to around 2.0, and 3 groups simultaneously runs at around 1.3. Sample Rate will vary from controller to controller and the PC used will also have some effect.

Some controllers (particularly AG4 transmissions and Digifant-III ECU's) use a "hybrid" data-type that requires reading a long header when changing group numbers. Viewing multiple groups still works with these data types, but the sample rate becomes extremely slow. If you see "Reading Header" all the time under the Sample Rate display, you'll know you've got one of these.