Basic of max232 problem occuring

[Monu johar]

I m using max232 with db9 and want to know that when we transmit bits serially from pc through db9 to max232's 13 pin, here we receive serial data in max.. But when we take output on 12th pin of max, is that pin always on high logic (3.68v aprox)..i think it should not be at high logic. Isn't it ? Please tell me.. Because i m having high logic on that pin(12th) before n after sending data bits.

 

[barry]

Forget about your db9. What does the signal on the max232 pin 13 look like? Do you have the proper capacitors installed? Do you have proper voltages at Vs+ and Vs-? Do you have a bad chip?

Wait a minute. You are seeing a high "before and after" sending data? What about WHILE you're sending data?

 

[Monu johar]

Thanku for reply...
Please see my thread below this thread, title as "serial comm. With laptop and at89c52"
there i have mentioned all in some detail.. Also i have take care of + & - pin of capacitors attached to max232N.