Interfacing Arduino with other Programs

Is there any way to have an Arduino link up with an already completed program that I did not create (I don't know if that's the correct term I am still new to programming). For example I have a multi-meter by BK precision that allows me to control it by hooking it up to to my computer. There is a program offered by BK precision that allows me to read and log the multi-meter capacitance measurements. What I want to happen is when I press the button on the BK precision program to start reading/logging measurements I also want the Arduino to switch on because I will be hooking the Arduino up to a multiplexer allowing it to access different positions of a connector by cycling through them automatically.

Please do not cross-post. Threads merged.

ddragon1999:
Is there any way to have an Arduino link up with an already completed program that I did not create (I don't know if that's the correct term I am still new to programming). For example I have a multi-meter by BK precision that allows me to control it by hooking it up to to my computer. There is a program offered by BK precision that allows me to read and log the multi-meter capacitance measurements. What I want to happen is when I press the button on the BK precision program to start reading/logging measurements I also want the Arduino to switch on because I will be hooking the Arduino up to a multiplexer allowing it to access different positions of a connector by cycling through them automatically.

That's going to be really hard to do without access to the source code for that application. Maybe you can sniff out the signal it sends to the multimeter.

https://bkprecision.desk.com/customer/portal/articles/1535377-communication-protocol-for-732a-and-735-sound-meter

...proves that B&K is willing to publish the protocol for at least one of their products. I suggest a few minutes with Google. If that effort fails the next step is to contact the vendor. If that fails it is time for reverse engineering. (From time to time I miss doing that kind of work. An odd combination of frustration, euphoria, and mania.)

A slightly different approach also might work. Instead of clicking the button in the application using a mouse, use the Arduino to click the button; you will need an Arduino that can act as a HID (e.g. Leonardo).

Note that ‘clicking the button’ can be either a command from the mouse or a command from the keyboard. E.g. a button [Start] (note the underlining of the S) can be accessed using S.

No experience with the Arduino as a HID though, so not sure how easy it is to send S.

sterretje:
No experience with the Arduino as a HID though, so not sure how easy it is to send S.

With Teensy (AVR) it is trivial.

The only caveat is the high speed continuous S strokes that are sent when one forgets a time delay / interlock. :o

Sterretje you are freakn awesome! Thanks for definitely pointing me in the right direction. My bad on posting twice.