Fixed Keywords

The keyword area  is divided into so-called reserved  (only used by the MIDAS system; you may read them but do not update them!), fixed  and user-defined keywords . The reserved as well as the fixed keywords are stored with their initial default values in the ASCII file MID_DISK:['MIDASHOME'.'MIDVERS'.MONIT]SYSKEYS.DAT  for VMS^7.2 and $MIDASHOME/$MIDVERS/monit/syskeys.dat  for UNIX. When starting the interactive monitor via INMIDAS in VMS (or inmidas in UNIX) this file is read in and the keywords initialized accordingly. Look at this initial keyfile and see if a keyword which fits your purposes already exists. For example, if you need a character keyword to hold the name of your output frame, use the fixed key OUT_A instead of creating a new one, since OUT_A just serves that purpose. Thus you save space in the keyword data base and standardize your program. Another example are the keywords INPUTI, INPUTR, INPUTC and INPUTD, which you should use whenever possible to hold the input values for your program.

For all the internal calculations  you need inside your procedure, you should always use local keywords  (see Chapter 3 of the MIDAS Users Guide for details).