Hi Everyone!

Need help in my new Project with Visual Basic 6..
I need to send a 5 volts signal from my pc using a VB6 program
to the serial port where I could place a relay...

Thanks :)

Dexter A.

10 Years
Discussion Span
Last Post by ymidexterous

You can try to do it with MSComm.RTSEnable = true.

If you dont know pinnings in serial port.

1 = DCD
2 = RXD#
3 = TXD#
4 = DTR
5 = GND
6 = DST
7 = RST
8 = CTS
9 = RI

I hope that will work. Just don't connect something that will burn your com port.


Oh i all most forgot comm port is +10 V when he gives signal and -10V when hes not active.

Correction of command for activation MSComm.portopen = true and voltage between pins 5-7 will be +10V when its disabled voltage will be -10V you will need some electronics to make it 0-10, diode and drive relay with transistor and external power supplay just to make sure u dont burn serial port.


i've connected the rs232 with an rs485 but the output voltage signal is still 2v.

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