Any function block parameter that is writeable has a lock assigned to it. You can change the lock assignments made by the system. Keys to all of the parameter and field locks (except Diagnostic) can be granted to specific plant areas. Refer to the following table for a default list of the parameter and field locks and a description of each lock's function:
| Lock | Assigned to parameters that… |
|---|---|
Alarms |
Concern alarms and the alarm horn. The Alarms lock affects access to the HORN parameter and the HENAB, MACK, and NALM fields. To acknowledge a horn, the current user needs the key to this lock for Area_A. |
Control |
An operator needs to write to in order to control the process. Examples of parameters with the Control lock are MODE, SETPOINT, and OUTPUT. |
Restricted Control |
Supervisors and engineers write to in order to configure the process. Operators typically do not write to these parameters. Examples of parameters with the Restricted Control lock are CONTROL_OPTS and DISABLE. |
Tuning |
Maintenance technicians and supervisors write to in order to tune performance. Typically (although not always), operators do not write to these parameters. Examples of parameters with the Tuning lock are GAIN, RESET, and HIGH_LIM. |
Diagnostic |
Affect diagnostic information maintained by the system, such as parameters that reset instance counts. |
System Records |
Affect the records kept by the system, such as parameters that turn off the recording of event records. |
User Locks 1 through 10 |
You specify. These locks provide flexibility to your security scheme. Note When Recipe Authorization is enabled, User Lock 06 through User Lock 10 are reserved for recipe approval signers. |