How do I actively toggle the DTR and RTS handshake lines of my com port?

[EddyMerckx]

I am hoping to piece together a very simple stepper control that requires using the two RS232 handshaking outputs as clock signals (DTR and RTS). The idea was to toggle the two inputs high and low 90 deg out of phase and connect them to a 2bit mux to generate the four waveforms needed for a stepper motor. If anyone has experience with the com interface and wants to offer a suggestion, I would be greatful.

-Dan Allis

[Ben]

After some thought i will have to admit this may work.

Be aware that updates of the port in a windows environment are not going to be deterministic.

Ben

[DiegoF]

Hi,

You can Toggle the DTR and RTS lines using the VISA properties under Modem Line Settings - Wire a property node with a VISA resource name to access these properties.

As Ben said, the lines would be controlled by software. This might be a problem if you have tight time constrains.

Diego F.
National Instruments.