Max sample rates seen with ScanXL Pro

[foca1]

looking to see how fast i can get data for the sake of troubleshooting sensor signals.

Assuming i use just a single PID, if that makes the sample rate any faster. Let's say i want to see the MAF signal. what kind of rates can i expect. say it's a GM, 2001.

For hardware, i have not made a purchase yet, but am willing to spend more to get faster rates.

[foca1]

going on over a week now.... NADA???

[Weston@PPE]

Sorry about that, I go over some things that effect the data rates here:
http://www.palmerperformance.com/forum/index.php?topic=5417.msg15382#msg15382

A 2001 GM would almost certainly use J1850, so I don't think you could beat an OBDLink. Anything more expensive would just be extra money that you wouldn't need to spend, since the faster hardware would just need to wait for the slower vehicle to give it more data.

[foca1]

thanks dude, appreciate the info. I am gonna pull the trigger on something, but i am trying not to blow money on something that is obsolete, and maybe a car that i will not have much longer. so i am looking for the right compromise.

Right now i have the 2001 suburban, which i am considering upgrading to a 2004 excursion. That's one consideration.

I also have an E90 (2006 330i) and an E36 (1997 M3). I am looking to acquire a honda insight (2002) or even a honda civic VX (1995) for some hyper-miling projects.... so, more to consider there...

So, i am thinking having CAN is a good thing for the future?>>>.... Analysis Paralysis DUDE!

help me out. Aside from that, how good is Palmer at these other brands, like honda and BMW? realizing that i prob won't get to the BMW lock-flippin-control module, or whatever the germans think of next. but maybe getting the basic engine PIDS would be a huge help for the future "issues" these car may have...

[Weston@PPE]

There are 3 widely used OBD-II protocols. Here they are slowest to fastest:
ISO
J1850 (VPW)
J1850 (PWM)
CAN

Generally speaking, Ford used J1850 PWM until they moved to CAN (starting in ~2004, all vehicles by 2008). GM commonly used J1850 VPW until the move to CAN (again starting in the 2004 area). Most other manufacturers, especially from outside the U.S., used ISO -- which is by FAR the slowest protocol. All manufacturers were required to move all of their OBD-II vehicles over to the CAN protocol in 2008.

ISO is the slowest protocol, at maybe 6 PID/sec. J1850 VPW can get 10-12, and J1850 PWM may get as high as 13-15. CAN is roughly 50x faster than J1850, and I've personally seen 150 PIDs/sec.

CAN is a good thing if you're looking for high data speeds, but isn't very widely used until at least 2006. I would guess (since I haven't connected to all of them myself) that the Suburban and Excursion will be J1850, and everything else you've listed would be ISO. Any OBD-II compliant car will work, so our software should work with all of those except maybe the '95 Civic because OBD-II wasn't standardized until 1996.

The OBDLink is the fastest budget interface you can get. I've seen 35-40 PIDs/sec using CAN with an OBDLink -- where many other (usually eBay chinese clone) ELM interfaces can't get much faster than 15 or 20 PIDs/sec. The OBDLink supports all OBD-II protocols, so it will work on any vehicle you buy.

Our software works with any OBD-II compliant vehicle, so as long as you get hardware that supports all of the protocols you should be able to use it on most of your cars. We don't lock the software to a single vehicle.

[foca1]

great info. thanks. I am gonna go with the OBDlink, but are all OBDlinks created equal. There's SX, MX, Wifi, bluetooth

I am mostly looking for data rates as fast as possible, now and in future CAN vehicles i will own. so.... are they all the same, in this aspect. I'd imagine the BT would be the slowest... BTW, what kinda baud rates are we talking here, just curious?

[Weston@PPE]

I responded in this other thread:
http://www.palmerperformance.com/forum/index.php?topic=5417.msg15522;topicseen#msg15522

[GaryDoug]

To answer the original question, I have a 1998 Pontiac, and the fastest reliable send/receive rate for that vehicle is in the area of 20 milliseconds per PID (resulting in about 50 readings/sec overall) That is without graphing or datalogging to slow it down slightly. Any ELM327-based adapter can handle that.