Help - Dash2 works and then feezes

[rbahr]

Hope to be at the track tomorrow... I have a dash2 connected to a DL1. After the car is on for ~ 5 min the Das2 display freezes with whatever is being displayed -

1st question - can the RS232 connection cause this is I have mucked things up? Is there supposed to be a crossover between the Dash2 and the DL1?

Thanks

Ray

[Peter Carroll/Toronto]

I've had problem like this related to bad serial connections. Vibration in a race car is hard on the connections. I've had bad cables (the cheap grey one). Also broken solder connections within the black RT shells. Or the screws could just be loose and vibrating.

With the RT devices, the serial cable is more like a serial ring. One bad connection breaks the ring and you get stuff like this.

Also check you have the latest firmware on the dash. Though that was several years ago.

Could also be bad power. Cigarette lighters are notorious. Use a hard connection even if it's just to the back of the cigarette lighter.

[rbahr]

I think I found it. I found a ground loop and wired in a good solid ground, I also removed the Dash2 config file from the DL1///

Thanks

Ray

[osborni]

Also - make sure you don't push anymore data to the Dash2 then you really need. 5hz is sufficient for most data. 25hz for RPM. Turn off channels from the DL1 that you don't need.

There isn't any flow control or error checking in the serial ring. Any corruption or overflow will freeze the dash.

[rbahr]

Thanks!

Why is this interface so badly designed? It is not at all difficult to avoid a lot of these problems...

Ray

[osborni]

It's not "bad", just consequences of choices.

My understanding (my assumptions and with conversations with R-T) is that the choice of communications technology to control costs limits the available bandwidth - which requires removal of error checking and flow control.

It works great as long as you don't flood the bus and have well done wires. Shorts to grounds will flake out any communications technology.

I don't think I've had a lock up of the Dash in the last 3 years or so. Better firmware and getting smart about the DL1 config files.

[rbahr]

Perhaps 'bad' was not the best choice of words. Having designed fairly complex communication systems for the last 30+ years, I make some assumptions, no flow control and simple ring architectures make for systems that are less tolerant to faults and there are better easy ways. Also I am more than willing to pay a bit more so that I need to know less...

Granted, installing the gear with a ground loop was pretty dumb on my part

Thanks for your help and experience. I have not seen any more lock ups since I made the few changes I did.

Ray