Switch item in web-gui to send Zwave command. Seems not related zwave bindings log in openhab.log

Here is my configuration,
Switch Z_socket1 “Living Room” (Lights) {zwave=“5:command=SWITCH_BINARY”}

.zwave:aeon_dsc06_00_000:1 []

Switch item=Z_socket1

openhab.log observation
However, when I switch my Z_socket1 on web-gui, only these shown in openhab.log,
2016-03-23 18:51:48.020 [INFO ] [smarthome.event.ItemCommandEvent ] - Item ‘Z_socket1’ received command ON
2016-03-23 18:51:48.021 [INFO ] [marthome.event.ItemStateChangedEvent] - Z_socket1 changed from OFF to ON

More related information is here,

Can some expert shed some light for my problem?
Thank you very much.