It is possible that the version software on the Calmotion unit is so old that larger USB disks stop working. The original versions supported USB disks with a maximum of 1 GB. Larger USB disks will not function. These are typically units manufactured before year 2009.
Typical errors you might see:
ERROR(17) No Response to Command 1
Device Detected P2
To find the version of the USB unit used with a Fadal, display the help menu by entering the CD,# command and then just press the + to display the help menu. The version is shown on the top line. The version must be higher than 1.8.0, and if there is a number in (), look for (03.66) or (V2C01) as acceptable versions to use with FAT32 disks. (NOTE: exFAT USB disk will not work, it must be a true FAT32 disk).
USBCNC-FAD units with a version 1.7.x must be updated to support larger USB disks. These units will need to be shipped to Calmotion to update the board to allow FAT32 USB disks. Call or email Calmotion to determine the cost or if a new unit will need to be purchased. It is $50 if the unit can be updated. Send the unit with your contact information and why you are sending the unit to Calmotion. Ship to:
7536 San Fernando Rd
Sun Valley, CA 91352
The alternative to not updating, is to continue to use any USB disk that is 1GB or smaller disk. These will typically have to be found on the used market.