How eXcontrol turns an LED installation on, puts it to standby and turns it off, for one screen or a whole venue. This covers what each button does, who decides, the order things happen in, and the rules that protect the hardware. New to this? Start with the simple overview.
1 · The short version
The power bar at the top of the dashboard controls the whole room. It shows the room's state in one word and the next scheduled change. Turning the room off or to standby needs a second tap to confirm.
A group (e.g. LED wall, Screens) is a named set of devices with a target: On, Standby or Off. If a device is in two groups, it follows the higher target, so switching one group off never cuts something another group still needs.
A device fed by an Expromo EPS power unit is turned off by switching off its relay. eXcontrol starts units one at a time, never cuts power that something else still needs, and checks every command it sends.
eXcontrol carries out a change once, then watches. If someone turns a screen back on with a remote or another controller, eXcontrol doesn't switch it off again. It shows a pop-up so you know.
2 · The pieces
An Expromo EPS has six relays ("outputs"). During setup, each device is given Powered by: which EPS feeds it, and optionally which one output. That setting is all eXcontrol knows about the wiring, so it has to be right.
A device with an output set owns that output. Devices without one share all the rest. A device with no Powered by is on its own socket.
For the network switch or the control PC. The room, a group or a schedule never switches it off, because eXcontrol would lose its own connection. Its own button in Power › Details still works.
Outputs that no configured device depends on (lights, passive loads, a spare unit) follow only the room. A group never touches them.
3 · Who decides
Buttons and schedules never switch devices directly. They set a target on the room or on a group. eXcontrol then works out each device's target and carries it out.
4 · On · Standby · Off
| Device | On | Standby | Off |
|---|---|---|---|
| Anything on an EPS | Its output(s) switched on, then an eXview is woken and a NovaStar is un-blacked | Power stays on. eXview → Standby, NovaStar → Black | Its output is switched off. The EPS decides, with no soft step first. |
| eXview on its own socket | Woken (wake packet, or the power-on command from Black) | Deep Standby | Same as Standby, since there's no relay to cut |
| NovaStar H-series / COEX on its own socket | Black released | Black | Black |
| Off, but its output also feeds a device that must stay on | n/a | n/a | Stays powered. It goes to Standby / Black instead, and its card says who it's kept on for. |
5 · Order of work
Each change runs as one job, in a fixed order. If a newer change arrives while a job is running, the newer one wins. Progress is shown live in the power bar.
6 · EPS safety rules
Each rule comes from testing a real unit. eXcontrol applies them to every command, wherever it comes from: the power bar, a group, a schedule, Companion or the API.
On a partly-on unit, POWER_ON first switches everything off, then re-sequences, so running equipment loses power for about 1 s. eXcontrol only sends POWER_ON to a fully-off unit. Otherwise it switches on just the missing outputs.
A single-output command sent during the unit's own sequence aborts it, and the remaining outputs never come on. eXcontrol waits for the sequence to finish.
Two connections at once can make the unit drop both commands, then ignore everything for ~10 s. eXcontrol keeps one queue per unit, and status checks wait while a command runs.
Every command is confirmed by reading the status back, and retried up to 3 times if it didn't take. Repeating a command is harmless. This also recovers from collisions with other controllers.
An output stays off at least 30 s before it's switched on again. This protects inrush limiters, and processors and Android screens aren't hard-cycled. eXcontrol shows a notice while it waits. It can be set per unit.
An EPS is shown as Not responding only after 3 missed status checks in a row, not after one lost reply.
7 · After power returns
When an EPS comes on, its equipment gets up to 4 minutes to start before a missing device counts as a problem. Meanwhile the room shows Starting… and names what it's waiting for. A device whose own output is switched off is expected to be silent. It shows No power, not a fault.
A scene can be marked as the power-on default for one EPS, or for all. When that EPS goes from off to on, eXcontrol waits 4 s, applies the scene, and applies it again 9 s later (controllers sometimes overwrite settings while they finish booting). It only covers devices on that EPS.
It only runs if eXcontrol saw the unit off first. Restarting eXcontrol next to a wall that's already on doesn't reset anything.
8 · Schedule
| Part | How it works |
|---|---|
| Actions | Turn on, Standby, Turn off, or apply a scene. |
| Target | The room, one group, or one EPS unit (whole-unit power, still with every safety rule from section 6). Standby isn't possible for a single EPS unit, so such an entry is skipped. |
| Days | Pick the weekdays. With none picked, the entry runs every day. |
| Warning | Before a Turn off or Standby entry, a full-screen warning appears in the last 15 minutes. It names what will switch off and can be dismissed. |
| Extend by 1 hour | Available in the warning and in the power bar, up to 12 hours in total. It applies to that one entry only. Other entries still run on time, and when the extension ends only that entry's own target is switched. |
| Precision | The schedule is checked every 20 s, so an entry runs within the first 20 s of its minute. It follows the PC's clock and time zone. |
9 · What you see
Every card, row and bar uses the same words and colours. Red means someone needs to look. Nothing else is red.
| Word | Meaning |
|---|---|
| OnPartly on | Running. Partly on: some displays are on, others aren't, or an EPS has some outputs off. |
| BlackStandby | Picture off, device still reachable. Black comes back instantly. Standby takes 30–70 s to wake. |
| Starting…Waking…Going to standby…Turning off… | A change is in progress. The power bar shows what it's working on, e.g. "Powering on EPS 2" or "Waiting for H9". |
| OffNo power | Switched off as intended. No power: its EPS output is off, so it's expected to be silent. |
| Not responding | Should be reachable but isn't. Check its power and network. |
Each card says which group decided, e.g. On · via Screens. When an Off device is kept powered for another device, its card says so, e.g. power stays on, output also feeds H9.
If something comes back on after it was set to Off or Standby (a remote, a wall switch, another controller), a pop-up says what and when, e.g. "eXview turned On after it was set to Standby (Schedule: Power off, 17:00)." Dismiss it, or leave it for the next person.
10 · Other controllers
Other control systems should send requests to eXcontrol instead of to the EPS directly. That way the same order of work and the same safety rules apply to their commands too. Group actions aren't in the Companion module yet, but its Generic HTTP module can call these directly.
| Action | Request | Body |
|---|---|---|
| Room or group: On / Standby / Off | POST /api/groups/<id>/stateall = the room | {"state":"on"|"standby"|"off"} |
| Room on / off (same as the power bar) | POST /api/power/all/on · /off | none |
| One EPS unit on / off (safe) | POST /api/power/<eps-id>/on · /off | none |
| One eXview: On / Black / Standby | POST /api/devices/<id>/zones/-/power | {"state":"on"|"blackout"|"standby"} |
| List / save groups | GET · PUT /api/groups | PUT: {"groups":[…]} |
| Dismiss a pop-up | POST /api/alerts/<id>/dismiss | all dismisses every one |
| Everything, live | GET /api/state | includes groups, deviceTargets, alerts |
If an access password is set (Setup › Access), it protects everything, including these requests. A controller logs in once and sends the bearer token it gets with every request. The token is valid for 30 days or until eXcontrol restarts. See Security.
11 · Not yet
No nested groups. Group targets aren't kept across a restart.
All EPS units are started one after another. There's no per-circuit "feeds" setting yet to run separate supplies in parallel.
No exception dates (holidays). An entry missed while eXcontrol was down isn't caught up afterwards.
No group or eXview actions in the Companion module yet (use Generic HTTP).
Every browser sees the whole room. There's no per-tablet scoping to one group yet.
POWER_ON from partly-on that only adds missing outputs, a "busy" reply instead of dropping, a start offset per unit, and the firmware version in POWER_STATUS.