Forcing values

Everything else in the editor shows a machine. This one changes it: a valve opens because somebody typed a number on a laptop. Forcing is a commissioning aid — for checking wiring, exercising an output before the sensor exists, or proving an interlock — and it is not a way to run a machine.

Open it from Online → Force.

What it does

A forced tag is held by the panel, not by the editor. The value is written into the tag on both sides of the program: before the logic runs, so the logic reads it, and after, so an output the logic just wrote is overridden. That is the standard scan model — anything else would make forcing an input work and forcing an output quietly not.

The program cannot win against a force. That is the point, and it is why the rules below matter.

How long it lasts


Released when you release it	yes
Released when the editor closes or the cable is pulled	no
Released by a power cycle	yes — the table is RAM
Optional timeout	yes, in seconds; `0` means hold until released

Closing the editor deliberately does not release a force: a technician who forces a valve open, walks around the machine and comes back expects to find it open. A power cycle does clear it, because a panel that came back from a power failure still holding somebody's value would be a trap — and unlike an S7, this panel has no dedicated lamp to warn about it.

A forced tag that is retentive keeps its last value

Forcing is gone after a restart, but if the tag itself is retentive, the value it was left at survives — that is the tag's property, not the force's. The program owns it again from the first cycle.

Nothing is silent

Every set, release and expiry goes into the panel's diagnostic buffer, so the machine's own log carries what was held and for how long.
The editor's status bar shows FORCED n in a colour that belongs to nothing else, on every page, and clicking it opens this window.
The list in the window is what the panel reports, never what this editor asked for. The two differ the moment a force expires or somebody else releases one, and the machine is the party telling the truth.

Using it

Pick the tag from the list (the filter takes a substring).
Set the value. A BOOL gets a checkbox; a number gets a field; a TIME tag is forced in milliseconds.
Leave the hold at 0 to keep it until you release it, or enter seconds for a timeout the panel enforces itself.
Force this value.

Release one with the button next to it, or all of them with Release all — which is never disabled while anything is held.

Limits and refusals


Forced tags at once	8
Longest timeout	1 hour
Requires	ONLINE, the same program in editor and panel, and a licence

Eight is deliberate. Somebody who needs to force nine things at once is not commissioning any more, they are rewriting the program — and that belongs in the editor, not in a live machine.

This is not a safety function

Forcing bypasses your program's logic, including its interlocks. It does not bypass hard-wired safety — emergency stop, doors and light curtains are wired, not programmed — and nothing here changes the rule that safety is never routed through the panel.