The routine obtains access to an existing NDF through the ADAM parameter system, associates it with the named parameter, and issues an NDF identifier for it.

CALL NDF_ASSOC( PARAM, MODE, INDF, STATUS )

PARAM = CHARACTER $\ast$ ( $\ast$ ) (Given)

MODE = CHARACTER $\ast$ ( $\ast$ ) (Given)

INDF = INTEGER (Returned)

STATUS = INTEGER (Given and Returned)

• If ’WRITE’ access is specified, then all the NDF’s components will be reset to an undefined state ready to receive new values. If ’UPDATE’ access is specified, the NDF’s components will retain their values, which may then be modified.

• If this routine is called with STATUS set, then a value of NDF__NOID will be returned for the INDF argument, although no further processing will occur. The same value will also be returned if the routine should fail for any reason. The NDF__NOID constant is defined in the include file NDF_PAR.