Hi!

I've built the one transistor Interface (http://winaldl.joby.se/interface2.gif without R3/R4) to read the ALDL stream from a 8746 ECM with WinALDL, but it doesn't seem work.

As far as I understand it, the Interface should convert the 5V Signal to 12V and invert it. I've checked my Interface several times. Is has 12V at the RX Pin when the Data Line is connected to GND. When I connect the Data Line to a 5V source, the RX Pin is 0V.

I used a Cathode-Ray Oscilloscope the verify that there is a signal at Pin E. And there is a 5V Signal. At the RX-Pin of my Interface its a 12V Signal which is inverted. But WinALDL doesn't do anything...

Do I missunderstand the way the Interface should work or am I just to dumb to use WinALDL?

I hope someone can guide me to the right direction.

Greetings from Switzerland
Mat



BTW. The Laptop has a built-in RS232 Interface which works and the COM-Port is correctly selected in WinALDL.

 

anyone? I'm getting

 

The 1 and 2 transistor ALDL interfaces don't always work. Sometimes they will work with one laptop but not another.

For WinALDL try both 2400 baud and 4800 baud. Sometimes one speed works better then the other.

RBob.

 

Thanks for your reply, RBob.
I've just tried a different Laptop with a USB-to-Serial converter. But it didn't work too. 2400/4800 testet also...

Is there another free Software to check if ALDL works? Do you know if I would see some characters when I start the Hyper Terminal instead of WinALDL? I would say yes, but I'm not sure.

Mat

 

You should see something. The '8746 ECM transmits all of the time.

RBob.

 

I just built the MAX232 Interface. And it works with the built in COM-Port and with the USB<->Serial converter! ;-)