This article explains how to set the scanner to only scan in cap locks.
Each scanner will have a different manual so ensure you have the correct manual. They way the scanner is attached to the PC is also very important so please confirm the connectivity.
For this example we are going to use the Symbol LS4278 with USB connection.
Please download the manual for the scanner.
Settings to enable:
1) USB Caps Lock Override (PG 151)
2) Simulated Caps Lock (PG 154)
3) Convert Case (PG 154)