Using the same VISA-device in several subprograms in the same main program.

[Tzench]

What I meant was if it needed one case for initializing, and another for opening.They could obviously go by any name.

Anyway, I've made an attempt at this. It doesn't work; it gets a lot of error messages, most of them being of the "missing assignment to tunnel" variety. I suppose

this could be solved by assigning empty string constants to the appropriate terminals.

More problematic are "Shift register: data type is undefined". I can't disagree with that : ), but it is what is supposed to make my action engine an action engine.

It also gets "Selector values have wrong type" in the case structure. This is a bit weird as a case structure is supposed to be able to take an enumerated variable as a selector.

[Dennis_Knutson]

You have some basic problems in your VI. First, you don't have an enum as a control. It's a ring control and they are not the same thing.

No, you don't need separate cases for the serial port init and VISA Open. When you call VISA Initialize Serial Port, a session will be automatically opened.

You can simply place the Read Buffer terminal inside the 'Read' case.

[RavensFan]

The problem with your shift register with an unassigned type is that it is just an extra shift register that never has anything wired to it and doesn't do anything.

With the other comments that have been made, here is a cleaned up version of your action engine.

Message Edited by Ravens Fan on 02-07-2009 09:58 PM