Modulating Valves

Hi I am looking at a way to modulate some water valves,(16 in total).
The scenario is when GA1 on the Set GA2 ON for 10Mins and Then OFF for 5Mins. And as long as GA1 is On then then it keeps repeating.

Now I have done this using logic timers, but cant do the full 16 valves as each GA Group takes two logic Timers, PAC cant have more than 20 timers.

Has anyone got any ideas

 

You can do this without any timers. Just count down each minute yourself. Since you have to do the same thing for 16 valves you can create an array of the ga's and times and just loop through them each minute:

Code:

//Global variables

valveEnableGAs: array[0..16] of char;
ValveOperateGAs: array[0..16] of char;
ValveCycleTimes: array[0..16] of char; // Total time in minutes between the start of each cycle (i.e. OFF time + On time
ValveOnTimes: array[0..16] of char; // On time in minutes;
ValveStartDelays: array[0..16] of char; // Delay  on startup for each valve (minutes);
ValveCounters: array[0..16] of integer;
ValveNo: integer;

// Initialization

valveEnableGAs := #1#3#5#7#9#11#13#15#17#19#21#23#25#27#29#31;  // These are the 16 GSa that enable the valves
ValveOperateGAs := #2#4#6#8#10#12#14#16#18#20#22#24#26#28#30#32; // These are the GAs of the valves
ValveCycleTimes := #15#15#15#15#15#15#15#15#15#15#15#15#15#15#15#15; // Time, in minutes, for each complete cycle (i.e. OFF + ON)
ValveOnTimes := #10#10#10#10#10#10#10##10#10#10#10#10#10#10#10; // Time each valve is on (minutes);
ValveStartDelays := #0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0; // Number of minutes to delay each valve at startup
for valveNo := 1 to 16 do valveCounters[ValveNo] := ord(valveStartDelays[ValveNo]); // Set initial delays

//Module

if second <> 0 then exitModule;  // Seconds = 0 once every minute
for valveNo := 1 to 16 do  // Loop for all 16 valves
begin
  valveCounters[ValveNo] := valveCounters[ValveNo] - 1; // Decrement minute counter for valve
  if valveCounters[ValveNo] <= 0 then  // If <= 0, timer expired, so start next sequence
  begin
    valveCounters[valveNo] := ord(ValveCycleTimes[ValveNo]); // Reset cycle timer
    if GetLightingState(ord(valveEnableGAs[ValveNo])) then // Only if enabled
      PulseCBusLevel("Local", "Lighting", ord(valveOperateGAs[valveNo]), 100%, "0s", ord(valveOnTimes[ValveNo]) * 60, 0%); // Pulse the valve for the on time
  end
end;

The global variables just define all the arrays to hold the data, which is setup in the intialisation section. I use character arrays here because you can intialise them in a single line. With integer arrays you can only initialise one element at a time.

The module first checks if seconds is zero, which will only occur at the start of every minute. It then loops though the valves one at a time. It decrements the current minute counter for the valve, and when it gets to zero, resets the count and the pulses the valve ga for its ON time if the enable GA is ON.

Currently if the enable GA is turned OFF the cycle will run to completion and then stop. You didn't say how you wanted that to work.

I haven't run this, but is compiles fine and the idea is sound. If you want to limit the number of valves, just change to FOR loop from 16 down.

 

Ashley.
Many thanks will give code a try soon.
I was looking at arrays and got the on working fine, but couldn't get the off to go. I made it harder by using discrete ON and OFF lines, rather than your Pulse command.

PS. yes when the control group goes off at any point then the Valve GA will also go off.

Thanks for your help.