Oversensitive Sin/Sout pins...

Scott M

I have a complicated application involving 2 Javelins, and one of them needs to be reprogrammed frequently. I've noticed an odd and annoying problem - when I plug a serial cable into the RS-232 connector I've wired to the Javelin sin/sout pins, the Javelin hangs, whether or not there's anything connected to the other end of the cable. After I power it down and back up, it's fine, and will run happily with the dangling cable connected. I assume the cable has just enough capacitance to make the Javelin think a reset was called for, but it happens with every cable I've tried. It sometimes happens when the cable is pulled off, too.

Is there any simple "buffer" circuit I can put between the Javelin and the connector, that will make the Javelin immune to (what I assume is) spurious capiticance changes?



·

Peter Verkaik

Do you have the 2 capacitors on the ATN line?

Without them you might experience the problem you described.

With the capacitors (0.1 uF) in place this should resolve

that problem.

regards peter