Toggle

A switch over a Boolean point that follows the plant: the click writes, the plant confirms.

Toggle is a switch over one writable Boolean point. It follows the SCADA rule of state ownership: the visual follows the point, refreshed from the live address space, and the click only writes the negation of what the point currently says; the switch flips when the plant confirms. The screen never shows a state the point did not report. It is a Control component; a new one occupies 4 × 1 cells.

Content

Data

Under the field, the editor shows what the chosen point reads right now.

When the switch can be operated

The switch is enabled only while all of these hold:

• the point resolves to a legal write target: a memory variable (not an expression variable, whose value is computed) or a tag that is not read-only;
• the point is reading in good quality: the click writes the negation of the current state, so with no trustworthy reading there is nothing to negate;
• no write from this switch is still in flight;
• the signed-in role may operate dashboards (see the permission model on the dashboards page). A role that may not shows the quiet lock mark instead, with the reason in the component's tooltip.

Write semantics

One click writes true or false (always the opposite of the point's last good reading) through the station's single logic write funnel, journaled like every other write. The transient answer line under the switch reports the outcome ("On written", "Off written", or the error) and clears itself after a few seconds. In a cell with no line for it and no corner title standing over the switch, the answer is written in the label's place beside the switch while it shows, a refusal in the error ink, with the whole answer in the tooltip; the switch does not move, the label comes back when the answer clears, and a switch with no label holds the same place for it. Authorization is re-checked at the moment of the click, so a role change or sign-out with the screen open cannot dispatch a stale press.

The switch is the one that waits for the equipment, not the Logic, so "On written" means the equipment took it. Anything else puts the refusal on that line in the words of whoever refused it: the station's own for what it settled before sending ("'Cmd' was not written: the device is not connected.") and the equipment's or its driver's for what happened on the wire. A state that a newer write to the same point overtook before it was sent is not a refusal and is reported as written, because the newer state is the one the plant is given.

If the bound point fails to read (unresolved address, or bad quality), the component wears the shared bad-reading mark and the switch is disabled until the reading returns.

The shared Appearance, Identification, Position and layer and Actions sections are described on the components page.