Motor and Flow Computer for Volumetric Flow Control

[Satchel]

Hello,

I am currently working on creating a closed feedback loop in LabView to control a motor (which controls a stepper valve) based on feedback from a volumetric flow sensor/computer. The motor is an Applied Motion Products' STM 23S-3AE and the flow computer is an Omega FC-22.The system goes as follows:

1. The user inputs the desired volumetric flow (ft^3/m)
2. The FC-22 reads the current flow value
3. Error is determined. Based on this error, the motor turns either CW/CCW to correct the flow to the desired value (the motor will operate at a constant speed in either direction until the flow is at the desired value)
4. This continues until the user halts the program.

I am having a few problems that I could use help with.

1. Interfacing the equipment with LabView

I have two issues with this phase:

1. The drivers for both components are installed and actively communicating with the computer via RS232. Using NI MAX, I am able to validate the flow computer in the serial port configuration, but am unsure what to do next in order to integrate into labview. The function of this component is to measure volumetric flow and report that value back in order to determine what the motor will do. I have read about visa and their functions, but can't quite seem to get the grasp of it.How should I proceed here?
2. As mentioned above, the driver for the motor is installed and works properly, however when I try to validate it in NI MAX, I get the following error:
   Error opening resource:
   ASRL 4::INSTR
   VISA: (Hex 0xBFFF0072) The resource is valid, but visa cannot currently access it.
   I have tried to validate with both the driver open and closed and got the same results. How should I proceed with this error and once complete, how should I proceed integrating into LabView?

2. VI Construction

LabView isn't something I generally work with, so I appreciate any advice or sample vis to point me into the right direction to construct this feedback loop. The system makes sense to me on paper but I know things can get tricky when programming.

I have attached the hardware manuals for both the motor and the flow computer,  as well as the host command reference for the motor. I am happy to explain anything in further detail if need be. I know this is a loaded post, so if you can only address one part that will still be a great help.

https://www.omega.com/Manuals/manualpdf/M2572.pdf

https://www.applied-motion.com/sites/default/files/hardware-manuals/STM23%20Hardware%20Manual_920-00...

https://www.applied-motion.com/sites/default/files/hardware-manuals/Host-Command-Reference_920-0002R...