UT_SYSTEM_MODE — The plant's mode: Off / Manual / Auto

Most sites have one mode for the whole plant on top of the device modes: Off
(nothing runs), Manual (run while someone holds a run request) and Auto
(the program runs the plant), often with a choice of auto programs. UT_SYSTEM_MODE
is that, with local / remote and a safe manual run.

Pins

	Pin	Type	Default	What to wire
in	`LocalRun`	BOOL	FALSE	Local manual run request, held: a run button held, a run switch, the local HMI's run button
in	`RemoteRun`	BOOL	FALSE	Remote manual run request, held (SCADA)
in	`RemoteEnabled`	BOOL	TRUE	FALSE: local control, `RemoteRun` is refused
in	`CommsOk`	BOOL	TRUE	FALSE: the remote link is down, `RemoteRun` is dropped (wire UT_WATCHDOG's `NOT CommsFail`)
in	`SwManual` / `SwAuto`	BOOL	FALSE	Plant selector switch (when `modeSource` uses it)
in	`ForceOff`	BOOL	FALSE	TRUE holds the plant Off (an e-stop healthy relay dropped, a tariff block). The chosen mode comes back after
out	`Mode`	UT_SYS_MODE		`UT_SYS_OFF` · `UT_SYS_MANUAL` · `UT_SYS_AUTO`
out	`IsOff` / `IsManual` / `IsAuto`	BOOL
out	`AutoType`	INT		The auto type chosen (1 … `autoTypes`). Your program reads it while `IsAuto`
out	`ManualRun`	BOOL		Run now: Manual, with a run request held
out	`Changed`	BOOL		One scan: the mode or the auto type has just changed
inout	`Data`	UT_SYSTEM_MODE_DATA		Settings, commands and status

Record `UT_SYSTEM_MODE_DATA`

Field	Type	Default	Meaning
`modeSource`	UT_MODE_SOURCE	UT_SRC_HMI	`UT_SRC_HMI` (cmdMode) · `UT_SRC_SWITCH` (SwManual / SwAuto) · `UT_SRC_REMOTE` (selector Off and Manual local, Auto hands over to cmdMode)
`powerUp`	UT_POWERUP	UT_PU_LAST	After a power cut or PLC stop / start: `UT_PU_LAST` the mode comes back; `UT_PU_OFF` back to Off
`autoTypes`	INT	1	Auto types offered: 1 … `autoTypes` (below 1 acts as 1)
`manualMaxRun`	TIME	T#0s	A manual run stops after this (0 = no limit)
`cmdMode`	INT	−1	HMI: 0 Off · 1 Manual · 2 Auto. Acts once when a new value arrives; anything else ignored. Set back to −1
`cmdAutoType`	INT	−1	HMI: 1 … `autoTypes`. Acts once when a new value arrives; anything else ignored. Set back to −1
`mode`	UT_SYS_MODE		status
`autoType`	INT		status: the auto type chosen (kept over a power cut)
`manualRun`	BOOL		status: a manual run is on
`runFrom`	UT_CMD_FROM		status: who holds it: `UT_FROM_LOCAL` · `UT_FROM_REMOTE` (local first when both) · `UT_FROM_NONE`
`runTime`	TIME		status: how long the manual run has lasted (0 when not running)
`timeLeft`	TIME		status: manual run time left (0 without `manualMaxRun`)
`remote`	BOOL		status: `RemoteEnabled`
`statusCode`	UT_STATUS		status: see Status codes
`faultId`	UT_FAULT		status: the setting that keeps it off (`UT_F_MANUAL_MAX_RUN`), else `UT_F_NONE`
`statusText`	STRING(30)		status: `statusCode` and `faultId` in words, e.g. `Manual: running (remote)`. The auto type is in `autoType`, the time left in `timeLeft`

How it works

The mode works as a device mode (UT_MODE_SELECT): from the
HMI, a selector, or both, starting at Off, with powerUp deciding what comes back
after a power cut. The auto type is kept over a power cut in every case.
Commands act once, when a new value arrives; with two masters put
UT_CMD in front of cmdMode.

Manual run: ManualRun is on in Manual while a run request is held:
LocalRun, or RemoteRun while RemoteEnabled and CommsOk. Drop it and the
run stops. A request must be released and given again before it runs:

after a power cut or PLC start (a run switch left on doesn't start the plant);
after the mode changes (entering Manual with the button held);
after the remote side was refused (local control) or cut off (comms lost),
so a stale SCADA request never restarts it;
after manualMaxRun has run out.

Auto: the block only says Auto and which type. Your program runs the plant from
IsAuto and AutoType. A manual request does nothing in Auto.

Retained: only the mode (as UT_MODE_SELECT) and the auto type, each saved only
when it changes.

Status codes

statusCode is a UT_STATUS (an HMI reads its number); statusText is the same in words.

`statusCode`	`statusText`	When
`UT_ST_OFF`	`Off`	Mode Off
`UT_ST_IDLE_MANUAL`	`Idle: Manual, no run request`	Manual, no run request held
`UT_ST_AUTO`	`Auto`	Auto (the type chosen is in `autoType`)
`UT_ST_MANUAL_LOCAL`	`Manual: running (local)`	A manual run held by `LocalRun` (`timeLeft` with `manualMaxRun`)
`UT_ST_MANUAL_REMOTE`	`Manual: running (remote)`	A manual run held by `RemoteRun`
`UT_ST_FORCED_OFF`	`Blocked: forced off`	`ForceOff`
`UT_ST_SELECT_MODE`	`Waiting: select a mode`	`UT_PU_OFF`, selector found in Manual or Auto at power-up: move it
`UT_ST_MUST_CYCLE`	`Waiting: command must cycle`	A run request must be released and given again
`UT_ST_MANUAL_MAX_RUN`	`Manual: max run, release run`	`manualMaxRun` ran out
`UT_ST_REMOTE_REFUSED`	`Blocked: remote run refused`	`RemoteRun` under local control
`UT_ST_COMMS_LOST`	`Blocked: comms lost`	`RemoteRun` dropped: `CommsOk` FALSE
`UT_ST_CONFIG` + `UT_F_MANUAL_MAX_RUN`	`Config: manual max run`	`manualMaxRun` negative: no manual run until fixed

Using it

Plant(LocalRun := PanelRunPB, RemoteRun := SCADA_Run, RemoteEnabled := NOT LocalSw,
      CommsOk := NOT ScadaLink.CommsFail, Data := PlantMode);   (* autoTypes := 2 *)
IrrigationEnable := Plant.IsAuto AND Plant.AutoType = 1;
PumpDownEnable := Plant.IsAuto AND Plant.AutoType = 2;
Pump1Demand := Plant.ManualRun OR (Plant.IsAuto AND LevelHigh);

OpenPLC