You should see a device named something like /dev/tty.SLAB_USBtoUART or /dev/tty.usbserial .
Disclaimer: Always ensure you have a Time Machine backup before installing Kernel Extensions on macOS.
But here is where things get sticky: You just upgraded your inventory management system to a new MacBook Pro or an iMac, and suddenly, your trusty CRD-20 is a paperweight.
Keep Scanning: How to Install and Troubleshoot the Zebex CRD-20 Driver on macOS
Here is the safe path to getting it working:
Open Finder > Applications > Utilities > Terminal . Run: sudo rm -rf /Library/Extensions/SiLabsUSBDriver.kext (if it exists).