Hi,

I'm sure you understand - its a matter of figuring out how to provide the necessary circuit to make the controller happy, but first of all, identifying which circuit it is making the alarm.

Consider the four kinds of input / output & their ability to activate an alarm within the controller

Digital input - Yes
Digital output - No
Analog input - Yes
Analog output - Generally No.

The other consideration is Communications, but probably not applicable in this instance.

So, yes the alarm might be temperature feed back from the TQ head - unfortunately I do not know what kind of signal this is. Measurements could be taken from a serviceable TQ, or enquiry could be made through Danfoss.

However, chances are it some sort of resistive device that changes with temperature (as most temperature sensors are) & chances are it could be a Pt1000 ohm as often used by danfoss controllers.

I'd suggest acquiring a Pt1000 sensor & connecting it to your wiring in place of the TQ feedback sensor (terminal 35? + 36? in TQ head). It may be necessary to "warm" the sensor up in some hot water (to simulate a "warm" TQ head). If this happens to work its a matter of measuring the temperature of the water (with a thermometer) that keeps the controller happy, then referring to Pt1000 temperature / resistance charts, identifying the equivalent resistance & then installing a fixed resistor in the circuit for continued operation.

Getting a bit long winded now but....

Further clarification of TQ temperature sensor could be made by connecting Pt1000 to terminal 17 + 18 of Danfoss AKC315A & referring to service parameter u04.

Further again, if the chiller package happened to be available with different TX valve options from the factory - say conventional TXV versus Electronic XV - there may be a parameter in the chiller controller to alter this selection & then the controller would stop checking for this alarm condition.

Happy hunting.