What is FAM?

[thej178]

Hello everyone, I have been working on the NI5761 - Getting Started example to get myself familiar with LabVIEW FPGA and the hardware we will be using (NI5761 with NI7975R). In the example code, they mention a FAM Initialization VI. This subVI was used in the Host code, not the FPGA VIs. The code mentions "FAM Initialization - Once the bitfile is loaded the FAM must initialize itself before it is ready for use" in regards to the purpose of that VI. After some googling, I was able to find that FAM stands for File Alteration Monitor and that this allows to alleviate some high disk and CPU usage by being able to detect when files are modified or changed and notifying the system instead of having to repeatedly scan for changes. Wikipedia also mentioned that FAM is beneficial as it works on a great variety of platform regardless of the kernel. As far as the Getting Started Code goes, my idea simply from the code itself is that FAM signals that the the FPGA I/O Module was configured, meaning that the bitfile was loaded, but I am not sure if that is a correct assessment. I am not a computer engineer, I am merely a beginning electrical engineer. What should I know about FAM in regards to FPGAs? What information does this tell me or help me with?

[GatorChomp · Accepted solution]

Hi thej178,

In the FlexRIO world FAM stands for FlexRIO Adapter Module. Typically a FlexRIO device consists of two parts:

1. The FlexRIO FPGA Device - The NI 7975R
2. An Adapter Module providing IO and other application specific functionality - The NI 5761

At a very simplistic level: the FAM is an external module that connects directly to the FPGA I/O, and you may need to wait for communication between the two to start up and the FAM to be fully configured. 

If you need more information on the specific adapter module you're using, I recommend the FlexRIO help for that module:

NI-5791 RF Adapter Module for FlexRIO

[thej178]

Oh wow, that was way more straight forward than I thought. Thank you so much for taking the time to explain!