OC CDU Keys Not working

Var 50, name CDUKey, Link USB_KEYS
Var 51, name CDUExec
Var 52, name CDUFail
Var 53, name CDUMSG
This is the script I'm using. I had to disconnect the CDU for about a month because a new base was being built When I pluged it back in the keys didn't work anymore. The SIOC shows it's recognized with device number of 171. I tried adding the device number in the script but then NO OC devices worked. Once I removed the device number all other OC devices worked. What am I doing wrong. My Best Dave