avoid DTR assertion @ power up

[Mebin]

Hi,

I am using the DTR pin to control an external relay (SSR) to power up and down an instrument. When the computer powers up, the DTR signal asserts, confirming what Jan mentioned in her book pg. 45. This behavior is detrimental to my instrument as it would be on for a split second at power up and then turn off. I added skipEnumerations key in the registry setting to prevent windows from enumerating during boot (to avoid more cycles of turn offs and ons) but I have not been able to find a way to stop DTR assertion at computer power up.

Any suggestions anyone?

Thank you very much in advance.

Mebin

[Jan Axelson]

You could add a circuit that removes short pulses.

http://www.labbookpages.co.uk/electronics/debounce.html

[Mebin]

Thank you Jan.. I really appreciate your response.. I was looking more for a software solution but I don't think it should be a big deal to add a small circuitry in the link 

[Jan Axelson]

Yes, software would be easier but I don't know of a way to do it.