VB code for serial port
VB code for serial port
VB code for serial port
VB code for serial port
VB code for serial port
VB code for serial port VB code for serial port VB code for serial port VB code for serial port VB code for serial port VB code for serial port VB code for serial port VB code for serial port
VB code for serial port VB code for serial port
VB code for serial port
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Old 05-06-2009, 12:32 PM
auststud auststud is offline
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Default VB code for serial port


Hi

I want to obtain voltage (-15 to +15) from the serial port to apply it to MAX232. For this, I connected DTS and CTS together and DTR, DSR and CD together. I am applying 5V to pin 3(Tx) and pin 5 to ground. And, the oscilloscope to pin 2(Rx), to get positive and negative voltage. Are the connections correct???

I have tried with so many codes in VB, but I dont get anything, and just the line in oscilloscope blinks for 5-7 seconds. Plz help me. I will be really thankful.
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Old 05-10-2009, 11:47 PM
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mkarasVB code for serial port mkaras is offline
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Sounds like to me that you may very well have fried your COMM port.

Do you actually know what the MAX232 type device is and how it is meant to be used? Under normal circumstances this part is used to convert the signals coming from an RS232 port such as PC Comm Port into normal logic level TTL type signals so that they can be then wired into the UART of a component such as a microcontroller or other peripheral logic device. You would apply 5V power to the correct pins of the MAX232 part and then place and connect a set of four booster capacitors which will result in the device being able to convert its input +5V to about +/- 9 volts. This voltage is used to bias the output drivers of the MAX232 so that it can signal back to the RS232 port with swing both positive and negative.

From the way you have described what you are doing it seems like you have things all twisted around and mixed up. Search on the web, there is a plethora of information out there about using the MAX232. In the mean time I hope your PC's COMM port has survived.

- mkaras
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VB code for serial port
VB code for serial port
VB code for serial port VB code for serial port
VB code for serial port
VB code for serial port
VB code for serial port VB code for serial port VB code for serial port VB code for serial port VB code for serial port VB code for serial port VB code for serial port
VB code for serial port
VB code for serial port
 
VB code for serial port
VB code for serial port
 
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