Locking parameters to operators

I'm attempting to lock down the following items to operators:

  • alarm limit values (HI_LIM, LO_LIM, etc.)
  • operator alarm suppression (.OPSUP)
  • alarm enable (.ENAB)
  • alarm priority (.PRI)
  • alarm suppression timeout (.SUPTMO)

I can get everything to lock out properly, except the alarm limit values.  The only way I've found to lock these is to also lock out .CV.  This obviously causes other problems (locking out set point changes, silencing the horn, etc).  I've tried using the parameter locks, but they appear to be ineffective.  Any suggestions?

Thanks,

James

  • In reply to Stuart Jolley:

    Make sure you don't have "CV" defined in the field security.  Field locks take precedence over parameter locks.  If you have "CV" defined as say "Control", all the parameter locks will default to "Control" when writing to the CV field.  

    You should be able to put parameter locks on "HI_LIM", "LO_LIM" and they take effect.

    • Make sure 'CV" is not listed in the field security
    • Make sure the configuration on detail plates, etc writes to the "HI_LIM", "LO_LIM" and not some other parameter.
    • Put parameter locks on "HI_LIM", "LO_LIM"
  • In reply to Otto Von Steele:

    Otto's got it right.

    http://www3.emersonprocess.com/systems/support/bol1131/source/extfile/b_theory/html/param_funct_security.htm

    "...Locks and keys assigned at the field level override those on the parameter itself. This means that specific parameter fields can be open to a large number of users while the parameter as a whole remains generally restricted...."

    "...When users make write requests to a specific parameter field, the system checks for a lock on the field. If there is no lock, the system checks for a lock on the parameter itself. When there is no lock on the parameter, the default lock is used. Users can write to the field of the parameter only when they have a key corresponding to the lock. ..."