5.15.1. Notes on protocol handling 
With the COPY action, a complete protocol variant combination descriptor
(PVCD) or an individual protocol descriptor (PD) can be loaded from the
hard disk.
When a PVCD is copied, the variant table (VARTAB) is initialized in
the DB and all the PDs required for the PVCD are loaded.
A maximum of 14 PDs can be used in a PVCD. The loaded PDs are activated
automatically.
When individual PDs are copied, either an already loaded PD can be
overwritten or a free space can be searched or specified for the PD.
Once an individual PD has been loaded, it is deactivated.
After an individual PD has been copied, the CHANGE command for activation
of the PD must be sent in order to ensure that the active bit is set
and the call processing (CP) protocol is available. The command to activate
the PD is:
CHANGE-PRODE:SRC=PD,PDNAME=PD08,SEC=ORG,ACTIVE=Y;
With the CHANGE action, the contents of the PD memories
can be changed in both the general section (VARTAB) and the individual
protocol descriptors (PD). A PD can also be activated/deactivated.
Only a PD loaded with COPY can be changed.
To prevent call processing from accessing inconsistent data when a
PD (protocol file) is changed, the PD is disabled automatically with
the first CHANGE command. The PD must be reactivated explicitly with
the last CHANGE command (parameter ACTIVE).