Start the openhab-cli console and set Zwave to debug

[root@host openhab2]# openhab-cli console

Logging in as openhab

                          __  _____    ____
  ____  ____  ___  ____  / / / /   |  / __ )
 / __ \/ __ \/ _ \/ __ \/ /_/ / /| | / __  |
/ /_/ / /_/ /  __/ / / / __  / ___ |/ /_/ /
\____/ .___/\___/_/ /_/_/ /_/_/  |_/_____/
    /_/                        2.5.0-SNAPSHOT
                               Build #1507

Hit '<tab>' for a list of available commands
and '[cmd] --help' for help on a specific command.
Hit '<ctrl-d>' or type 'system:shutdown' or 'logout' to shutdown openHAB.

openhab>log:set DEBUG org.openhab.binding.zwave
openhab> log:tail
20:40:32.065 [DEBUG] [rnal.protocol.ZWaveTransactionManager] - 

follow the log

openhab> log:tail
20:40:32.065 [DEBUG] [rnal.protocol.ZWaveTransactionManager] - 

This will also show up in the the text logs like /var/log/openhab2/openhab.log

Set back to the default

openhab> log:set INFO org.openhab.binding.zwave

Exit

openhab> logout

See https://www.openhab.org/docs/administration/console.html for more details about using the console

for more details about using the console