I am having difficulties controlling Harvard Apparatus 11 Pico Plus model pumps. I am using Labview 8.0 and the latest release (10/05) of the Harvard Apparatus Pump 11 Series drivers.
Specifically, my problem is with the sub-VI entitled "Read Flow Rate.vi," which calls VISA Write during its run. When it attempts to write something to the pumps, an error is returned. "Special Read.vi" then comes after it, and also returns an error.
"Configure Flow Rate.vi" also calls VISA Write and Special Read, but works fine. And as far as I can tell, all the other calls of VISA Write and Special Read.vi in other programs work fine.
I've checked all the connections between my pumps and the RS-232 PCI card with 4 serial ports through which I connect them to my computer. I've made sure that baud rates (9600) and stop bits (2) all matched on the pumps, in Labview, and in Windows device manager.
If anybody could guide me in the right direction, I would greatly appreciate it. I'll post pictures of the code for "Read Flow Rate.vi" and "Configure Flow Rate.vi" soon.