Block Irrigation

The block controls a garden irrigation system with several zones. It opens the valves one after another, releases the master valve or pump, adjusts the run times to season and weather, and holds off when it rains, freezes, blows or the soil is still wet.

The zones have no inputs or outputs. They are entered in a table in the "Zones" parameter and switched through their group addresses. This keeps the block compact even with many zones.

Times and programs are set by the user in the Block Irrigation control element - from the app as well, without the studio. The block must be linked to that control element.

Presence comes from the Block Presence block, as with every block element. See also Presence in general.

For simple systems without program management the Irrigation block is still available.

Zones

The zone table is opened from the parameter window with the "…" button. Group addresses can be dragged into the list from the variable window; the column you drop on decides whether the valve, the feedback or the soil moisture address is set.

Valve address: Switched to open and close the zone.
Name: The label in the control element. The two characters in the name produce a line break there, for example "Lawn south side".
Feedback address: Optional. See "Valve feedback".
Soil moisture address: Optional. If it is entered, a moisture threshold can be set in the control element, above which the zone is skipped.

Every row of the table is one zone - no count has to be given anywhere else. At most 32 zones are run.

Everything else about a zone - Active, cycle, soak time, moisture threshold, output and the ignore rain, moisture, wind and frost flags - is set by the user in the control element, behind the gear in the run time list. These are values you tune on a running system; nobody should need the studio for them. On a system coming from an older version they are taken over from the zone table once, so nothing changes.

Programs and start times

A program holds how long each zone runs. A run time of 0 means the zone does not belong to this program. On top of that come a day pattern, a factor and whether the weather adjustment is used.

The start times are the schedules of the control element. Each schedule names the program it starts. That makes weekdays, sunrise and sunset, dates, "once only", the brightness condition and the calendar import available. Each schedule can also be limited to a presence state.

Without a schedule nothing starts. The day pattern of a program is not a start condition of its own but only an additional filter: it says on which days a program may be due at all - the moment always comes from the clock. A program set to "Every 2 days" with no schedule never waters. For "every day at 6 o'clock" you need a 06:00 schedule with all weekdays; the day pattern can stay on "By schedule".

The day pattern therefore applies in addition to the schedule: "By schedule" leaves the weekdays of the schedule in charge, "Every n days" waters only every n-th day, "Even days" and "Odd days" follow the calendar day.

A fixed weekly rhythm needs no day pattern - "every day" or "Monday, Wednesday, Friday only" is set in the schedule itself. The pattern is needed for rhythms that do not fit into a week: an interval of two days walks through the week and cannot be expressed with weekdays, and neither can three, four or five days. The same goes for even and odd calendar days. The interval therefore starts at two days; "every day" is already "By schedule" with all weekdays.

The rhythm is anchored to the day it is set on: choosing "Every 3 days" today waters today, in three days, in six days. Changing the interval later starts the count again from that day. It is pure calendar arithmetic - a restart of the controller or a power cut does not shift the rhythm, because no date is stored; every day is worked out afresh.

A season can be set, outside of which the program does not run.

Overlapping starts are never lost. If a second program starts while the first is still running, it is appended and run afterwards.

A program can also be started from the program page through input PS: the value is the program number, a change to 0 ends the current run.

Run time and factors

The actual run time of a zone is the time set in the program times the program factor times the seasonal factor times the weather factor. All factors are percentages; 100 % leaves the time unchanged.

Seasonal factor: One value for the whole year or twelve monthly values. This adjusts every run time at once instead of changing each zone individually.
Weather factor: It shortens the run times in cool, damp weather and extends them in heat. The block calculates it from the temperature, humidity and rainfall of the last 24 hours as soon as the weather adjustment is switched on in the control element. The three weights decide how strongly each quantity counts; 0 % turns it off. If a value is present at input WF, that value takes precedence - any source can then supply the factor and the internal calculation is dropped.

If the calculation gives a shorter time than the minimum run time, the zone runs for exactly that minimum. Anything shorter is not worth the switching operation because valves and sprinklers have to start up first - but the zone is not skipped for it. Only a run time of 0 in the program leaves it out altogether.

Cycle and soak

If the sprinklers put out more water than the soil can absorb, puddles form after a few minutes and the water runs off - on heavy soils and on slopes this is the normal case. The run time of a zone can therefore be split into sections.

Example: 20 minutes run time, cycle 5 minutes, soak 30 minutes. The zone runs four times for five minutes with half an hour of pause in between. During the pause the other zones keep running, so the total duration of the program barely increases.

A cycle of 0 lets the zone run through in one piece.

Holds

An active hold aborts a running cycle and prevents a new one.

Rain: Input RE holds immediately. In addition the block sums the rainfall at input RM over 48 hours; if it exceeds the set value, a rain delay applies. It can also be set by hand in the control element.
Frost: If the outside temperature at input AT drops below the limit, nothing is watered - icy paths and damaged pipes. If the input is not connected, the check is skipped.
Wind: Above the set speed watering is held off because the water drifts away. A value of 0 turns the check off.
Soil moisture: Per zone, see "Zones".
Hold and enable: Input SP holds, input FG enables. If FG is not connected, the block counts as enabled.

Valve feedback

Telegrams can be lost on the bus. A valve then stays closed although the command was sent - or worse, it stays open.

If a feedback address is entered in the zone table, the block waits the set time for the feedback after every switching command. If it matches the value sent, the monitoring is finished. If it does not arrive, the command is repeated.

After the set number of retries nothing more is sent: the zone counts as faulty, output SF is set and the status carries the "no feedback" flag. If the feedback does arrive later after all, the flag disappears from the status again - output SF stays on, though, until it is acknowledged through input QU. That way a valve that only answers now and then is noticed as well.

Without a feedback address no monitoring takes place.

Master valve, delay and parallel zones

Many systems have an additional shut-off valve or a pump upstream of the zone valves. Output HV switches either of them. The "Master valve" parameter says what is connected there:

None: Output HV stays 0. The zone valves are switched directly.
Master valve: HV is switched on when the run begins and stays open until the whole run is finished - between two zones and during a soak pause as well. The pipe stays filled and under pressure.
Pump: Like the master valve, but the pump is switched off as soon as no zone valve is open any more - during a soak pause as well. A pump must not run against closed valves and must not run dry; a soak pause often lasts half an hour.

The lead time makes sure HV switches first and the first zone only opens afterwards - a pump has time to start up before water is drawn. The follow-on time keeps HV on for the set time after the last zone.

The station delay sits between two zones. A positive value closes the old valve before the next one opens. A negative value lets both overlap and keeps the pressure up; the overlap only applies when one zone runs at a time.

"Zones in parallel" allows several zones to run at once. The value limits pressure and flow - more than the system can supply must not run together.

Water meter

If a counting water meter in litres is connected to input WZ, the block determines the consumption per zone and minute. The first complete run sets the nominal value; after that it is adjusted slowly as long as it stays inside the tolerance band.

Flow too high: Burst pipe or a broken-off sprinkler.
Flow too low: Blocked nozzle or a valve that does not open.
Flow without a valve: Water is flowing although no zone is driven - this is the actual leak detection.

Depending on the setting the block only reports, or additionally closes the master valve and aborts the run. Every message appears at output SF and in the log of the control element.

Presence

In the control element a program can be assigned to each presence state; it starts when the house switches to that state - for example a more economical program as soon as holiday mode is selected. If nothing is assigned for a state, the change does nothing; that is the default.

In addition, each start time can be limited to the states in which it applies at all.

Inputs
FG	Enable	Optional. 0 holds the whole block, any other value enables it. Not connected: the block counts as enabled.
PS	Start program	Optional. Every change of the value is acted on: a change to 1..8 starts that program, a change to 0 ends the current run and clears the queue. An unchanged value does nothing. Not connected: nothing is ever started through the input.
HA	Hold	Optional. Any value other than 0 pauses, 0 lets it continue. The valves close, the queue stops and continues afterwards. Not connected: it is never paused.
SP	Lock	Optional. Any value other than 0 holds: a running cycle is aborted and no new one is allowed. Not connected: never held.
RE	Rain	Optional. Rain sensor: any value other than 0 holds immediately, 0 releases. Zones set to "ignore rain" are unaffected. Not connected: watering is never held off because of rain.
RM	Rainfall	Optional. Precipitation in mm per hour. The block builds the sum of the last 48 hours from it for the automatic rain delay and uses the value for the weather adjustment. Not connected: there is no automatic rain delay and rainfall does not count towards the weather adjustment.
AT	Outside temperature	Optional. Below the set frost limit nothing is watered; zones set to "ignore frost" are unaffected. The value also counts towards the weather adjustment. Not connected: the frost check is skipped and temperature does not count towards the weather adjustment.
WI	Wind	Optional. Wind speed in km/h. Above the set limit watering is held off; zones set to "ignore wind" are unaffected. A limit of 0 turns the check off anyway. Not connected: watering is never held off because of wind.
LF	Humidity	Optional. Relative humidity in %. Counts towards the calculated weather adjustment. Not connected: humidity does not count there, the other quantities keep working.
WF	Weather factor	Optional. Factor in percent from an external source. If the input is connected, that value alone applies and the internal calculation is dropped. Not connected: the block works the factor out itself, provided the weather adjustment is switched on.
WZ	Water meter	Optional. Counting water meter in litres - the block evaluates the difference. Only with this input is the water volume measured and the flow monitored. Not connected: the water volume is estimated from run time and output rate, and there is no flow monitoring.
QU	Acknowledge	Optional. The change from 0 to any other value is acted on; it resets output SF and the reported valve faults. Not connected: faults are acknowledged in the control element.

Outputs
HV	Master valve	Master valve or pump, depending on the setting. Stays 0 if no master valve is selected.
PR	Program	Number of the program whose zone is currently running, 0 if none is running. Which programs are pending altogether is told by PA.
ZO	Zone	Number of the running zone, 0 if none is running.
RZ	Remaining time zone	Remaining run time of the running zone in minutes.
RP	Remaining time program	Sum of all outstanding run times in minutes.
NS	Next start	Minutes until the next start time within the coming 24 hours, 0 if none was found. Only schedules whose program is actually due on that day are counted - a disabled program, one outside its season, or one that its day pattern rules out announces no start.
WM	Water volume	During the run the amount used so far, afterwards that of the last run. If a meter is connected to input WZ it is measured - regardless of whether the evaluation is switched on. Without a meter it is estimated from the run time and the output rate of the zone.
SF	Fault	Missing valve feedback or a water meter message. The reason is shown in the control element in the "State" row and in the log. It is reset through input QU or by hand in the settings of the control element.
PA	Programs active	Bit field of all programs currently pending: bit 0 for program 1, bit 1 for program 2 and so on. Because overlapping starts are stacked, more than one can be pending - PR names only the one being run.
GP	Total time program	Total run time of the current run in minutes, with all factors applied. Together with RP it says how far the run has progressed.
ST	Info status	Every state in one number. Each state has its own bit, and several can be set at the same time. The Binary decoder block splits the value back into the individual states; its output B1 is bit 0. Bit 0 = 1: Running Bit 1 = 1: Held Bit 2 = 1: Locked Bit 3 = 1: Rain Bit 4 = 1: Rain delay Bit 5 = 1: Frost Bit 6 = 1: Wind Bit 7 = 1: Zone skipped Bit 8 = 1: Manual Bit 9 = 1: Soaking Bit 10 = 1: Flow too high Bit 11 = 1: Flow too low Bit 12 = 1: Flow without a valve Bit 13 = 1: No feedback

Parameters
Number of programs		This many programs are offered by the control element.
Zones		Opens the zone table.
Master valve		None, master valve or pump. The master valve stays open for the whole run, the pump switches off in every pause in which no zone valve is open.
Master valve lead time		The master valve opens this long before the first zone.
Master valve follow-on time		It stays open this long after the last zone.
Station delay		Pause between two zones. A negative value lets the zones overlap.
Zones in parallel		This many zones may run at the same time.
Minimum run time		A valve never runs shorter than this. If the factors work out to a shorter run time, it is raised to this value. The same time is used for "Test all zones" in the control element.
Rainfall for delay		From this sum over the last 48 hours watering is held off. 0 turns the automatic rain delay off.
Frost below		Below this outside temperature nothing is watered.
Wind above		Above this speed watering is held off. 0 turns the check off.
Evaluate water meter		Off, report only, or additionally close the master valve.
Permitted deviation		Tolerance band around the learned consumption per zone.
Feedback waiting time		The block waits this long for the feedback of a valve before it repeats the command.
Feedback retries		After this many unsuccessful retries the fault is reported. "No limit" never reports and keeps sending.
Push message		Sends a message to the apps when a fault occurs.

See also the common parameters of all function blocks.