Level Sensor State

[SteveAtkins]

What are the programmable logic inputs that give you the current states of level sensor 1 and level sensor 2?

I was looking at it in Control Centre and expected to see something like 'Level 1' and 'Level 2' but couldn't see either. P3 is running firmware version 3.14.

Thanks.

[Vinny]

You can see the states of the Level Sensors by clicking on "Probe/sensor controls", then "Level". All your level sensors are listed there with their current states.

[SteveAtkins]

I know that. What I want to know is how to incorporate those individual states as inputs to programmable logic gates.

[Matthias]

sensor states can't be used as inputs for the PL, it can only use outputs of a"control logic" (like pH-controller or level controller)

in your case you could use 2 level controls, one for sensor 1, the other for 2, use them as ATO

then use the "outputs" fill 1 and fill 2 for your purpose


but what do you want to do in the first place? maybe it can be managed easier?

[SteveAtkins]

I thought I had seen level sensors included in programmable logic inputs but maybe that was before you introduced water change functions into the system.

This is quite long - but hopefully very clear.

What I want to do is set up an auto water change that:
1. drains for a fixed amount of time then
2. fills until it reaches a level sensor.

Level sensors.

• Level sensor 1 (optical) is at the normal water level for the sump.
Level sensor 1 is used for:
o [CURRENT USE] ATO using a single sensor.
o [CURRENT USE] Top sensor for a manually started water change. This water change uses Timer 1 but this timer is not set up, so the water change can only be started manually.
o [PLANNED USE] Top sensor in timed automatic water change. This is what I am trying to set up at the moment – SEE BELOW

• Level sensor 2 (optical) is just above the main circulation pump input.
Level sensor 2 is used for:
o [CURRENT USE] Bottom sensor for a manually started water change. This water change uses Timer 1 but this timer is not set up, so the water change can only be started manually.
o [PLANNED USE] Detecting very low sump water level and turning off main circulation pump, skimmer, drain & fill pumps and raising alarm. I have not tried to set this up yet but suspect I will need to create a virtual sensor and use the leakage detection function. Will be disabled during manual water change.

Sockets

Sockets used for ATO and water change:
• ATO uses socket 4 for fill (fresh RODI water)
• Water change uses socket 19 for drain (old salt water)
• Water change uses socket 20 for fill (new salt water)

Pumps

Pumps for water change.
• When I do a manual water change I temporarily connect up two Eheim pumps to sockets 19 and 20.
• For auto water changes I plan to have two peristaltic pumps connected to sockets 19 and 20 (but could use other sockets if necessary). These will be permanently plumbed in with much smaller diameter hoses than used for manual water changes.

 
PLANNED Process

How I want auto water changes to work.

Pre-condition:
• Timer 2 has been programmed to set auto water change start time
• ATO must not be operating
• Manual water change must not be operating

Start
• When Timer 2 reaches programmed event start time:

Action if ATO is operating:
• Repeat pre-condition test every 10 minutes until pre-condition test is passed or 30 minutes have elapsed since event start
• If precondition test is not passed in this time:
• Raise Alarm
• End process

Action if manual water change is operating:
• End process.

Action if neither ATO nor Manual water change are operating:
• Disable ATO
• Disable manual water changes
• Turn off skimmer if it is on
o Note: skimmer only operates ½ of the day, turning on at 2 hourly intervals.
• Drain
• Stop Drain after 15 minutes
• Fill
• Stop Fill when water level reaches Level Sensor 1
o If water level has not reached Level Sensor 1 within 20 minutes
 - Raise Alarm
 - End process
 - Note: The peristaltic pumps will be identical but hose lengths and head may make flow rates slightly different – this is why I do not want to rely on timers to control both drain and fill.
• Return skimmer to previous programmed state
• Enable ATO
• Enable manual water changes (this does not mean start one, just allow them to be started)
• End process

[SteveAtkins]

... you could use 2 level controls, one for sensor 1, the other for 2, use them as ATO

then use the "outputs" fill 1 and fill 2 for your purpose....

That worked.

Used 'Fill x' (inverted) AND 'Always On' to give an output that was ON when water was above sensor.