Responsibility zones
A responsibility zone is a named group of signals that belong together in operation, for example the signals of one substation or one pumping station. Zones answer two questions: who may control these signals, and, with exclusive control, who controls them right now. Two operators in different control rooms can then share one project without operating the same plant at the same time.
Zones and signals
- A zone is a set of signals. A signal belongs to at most one zone; a signal without a zone is free and is not affected by zones.
- Zones are flat: they have no hierarchy. They are separate from the areas of the alarm system, which form a tree and group alarms for the lists.
- Zones are defined and assigned in the configuration editor; see Define responsibility zones.
Rights per profile
Each profile has two zone rights, both All by default:
| Right | Allows |
|---|---|
| View | Seeing the zone and its owner on the run screen |
| Control | Sending commands to signals of the zone |
A command to a signal in a zone the user may not control is refused with You do not have control rights for this zone. The server checks this for every command, whatever screen, script or interface it comes from.
Exclusive control
With Exclusive control on (off by default), a zone is controlled by one user at a time, the owner:
| Action | Who | Result |
|---|---|---|
| Take | A user with control rights, on an unowned zone | The user becomes the owner |
| Relinquish | The owner | The zone is unowned again |
| Request | Another user with control rights | The owner sees <user> requests control with Accept and Decline; without an answer the request drops after Request timeout (s) (30 s) |
| Force take | A user with control rights and the Take over control permission | The user becomes the owner at once; the previous owner is told |
Only the owner can send commands to the zone. Commanding a signal of an unowned zone asks You do not have control of this zone. Take control and send the command? with Take control and send and Request control.
- When the owner's session ends (browser closed, connection lost), the zone is released after Release after (s) (60 s). If the owner comes back in time, they keep it.
- The owners are kept in the memory of the gateway: when the gateway restarts, all zones are unowned again.
- If the zone settings are not available yet, commands to zoned signals are refused rather than allowed.
Every take, relinquish, request, acceptance, refusal, force and time-out is written to the event list as Area control. Operators take and relinquish zones with the Responsibility zones button of the run screen; see Take and hand over control of a zone.
Zones and other protections
Zones decide who may operate; they do not replace the permissions (Field writes is still needed for any command), the topological interlocks or the approval of critical commands. Server scripts are automation and are not subject to zones; keep their command targets narrow.