Controlling multiple pH-probes

we got this presales enquiry:

Hi,
I am interested in a profilx 3.1N system and have a few questions. I would like the system to monitor and control pH in up to four or six tanks (I gather this is possible via extensions) Is it possible to control the pH for each tank at a different pH?
Can the pH be controlled (by bubbling CO2) as a predefined pattern of pH that cycles each day?
Can the pH be controlled as an offset? E.g If I monitor the daily pH pattern in one tank can I get the controller the mirror that but add or subtract and offset?
Can I get the controlled to add a set concentration/volume of CO2 without adjusting for the pH recorded

Quote:

Is it possible to control the pH for each tank at a different pH?

yes, ProfiLux is able to manage up to 32 sensors, each sensor can have its own nominal value

Quote:

Can the pH be controlled (by bubbling CO2) as a predefined pattern of pH that cycles each day?

yes, the pH-control can be combined with a timer or our programmable logic

Quote:

Can the pH be controlled as an offset? E.g If I monitor the daily pH pattern in one tank can I get the controller the mirror that but add or subtract and offset?

yes, for this purpose we have the so-called "dynamic nominal value" which can use as input the reading of another probe, an offset can be adjusted.

Quote:

Can I get the controlled to add a set concentration/volume of CO2 without adjusting for the pH recorded

I am not sure what you mean. Do you want to record the on-time of the CO2 solenoid? With firmware 6.09 you can record the state of every socket.

Quote:

Is there anyway you can tell me how and what the customer needs to do the above?

- ProfiLux 3.1N or N eX
- 1 Expansion Box (has inputs for pH, temp, redox, cond., etc.)
- expansion cards, at least PLM-pH/Redox for additional pH-inputs

the exact setup depends on the environment - distance between controller and tanks, max. probe cable length possible, etc.
based on this we chose a more centralized or de-centralized system (e.g. expansion box on every tank, connection between them only over PAB bus system)
-> here we need more information about the planned setup