How can I control the voltage on the pins of a DB 9 pin connector?

[J.Diorio]

I have a Kent Scientific "Genie" Programmable Syringe Pump. The pump is capable of being controlled by a DB 9 pin connector. High or low voltage levels on the different pins will tell the pump to do certain things, like change flow rate, or trigger the pump. I'm interested in using LabVIEW to control the voltage inputs on each pin from a PC that also has a DB 9 pin connector. How can I do this?

[DiegoF]

Hi,

You can only control the state (asserted or deasserted) of some of the lines in the serial port, but not the actual voltage level. Asserted can be anything between -12 to -3 V, while deasserted goes from 3 to 12 V (inverse logic).

You only control manually the state of the control lines of the serial port. Use a LabVIEW property node and wire the VISA references. The properties you should use are under the "modem line settings". There are some lines that are read only (input lines).

Hope this helps.

DiegoF
National Instruments.