How to determine how many FPGA boards the system includes?

Description

When you use "aocl diagnose -probe" command to determine how many FPGAs the system includes, you might get following failure.

-probe is not a valid device name.  

The command suggested in OpenCL on Intel® Programmable Acceleration Card with Intel® Arria® 10 GX FPGA Quick Start User Guide(ug-qs-ias-opencl-a10-v1-0.pdf) is wrong

Resolution

Use "aocl diagnose" or "aocl list-devices" with no options to list all of the devices.