Mixing Valve Controller

FUNCTIONS

The heating mixer block provides mixer control for heating or cooling. It can be used with all common types of mixers (3-way valves and analogue 0-10V mixers etc).

For a three-way valve, the current position of the actuator is stored in the software. Once the position has reached 0% or 100%, a synchronization signal (a continuous on or off pulse which lasts 1.5-times the operation time) is sent to the actuator to ensure that it is in the correct position.

If the mixer hasn’t been in the 0% or 100% position in the last 24 hours, then a synchronization signal (a continuous on pulse lasting 1.5-times the operation time) will be sent to the actuator. The actuator is then immediately brought back to its original position.

A synchronization signal is also sent after each restart of the Miniserver.

BASIC SETUP

The desired target temperature can be set with the analogue input temperature T. The desired temperature can either be set with a virtual input connector or a timer switch.

An actual temperature reading from a temperature sensor in the respective room should be connected to the analogue input AI.
Activating the input stop St locks the outputs in their current states.

Mixing Valve Controller Configuration

OVERVIEW

INPUTS

TTarget temperatureConnect an analogue value here to set the target temperature, such as a timer/scheduler, a constant or a virtual analogue input.
AIActual temperatureConnect a 1-Wire or analogue temperature sensor here to measure the flow temperature.
StStop inputWill move the valve according to the parameter Sm.
DisDisable inputThis input will disable T. The last value for T to be entered is used and any further changes are ignored.

OUTPUTS

AQAnalogue outputConnect a 0-10V mixing valve.
Q1Digital outputConnect the open contact for a three-way mixer (hotter).
Q2Digital outputConnect the open contact for a three-way mixer (colder).
QeOutput errorThis output will be on when the actual temperature AI is either greater or lesser than the target temperature T by 5°C. If the stop input ST is active then Qe will be off.

PARAMETERS

RSets the mixer running timeHow long the valve takes to go from open to closed in seconds.
SAdjusts the sampling timeHow often the heating mixer will adjust the valve in seconds. Default setting is suitable for most heating control systems (typically flow temperature control with a three-way mixer). For more complex control systems such as a heating circuit with an exchanger this parameter may need to be adjusted.
KpGainDetermines the % gain of the controller. Default setting is suitable for most heating control systems (typically flow temperature control with a three-way mixer). For more complex control systems such as a heating circuit with an exchanger this parameter may need to be adjusted.
KiIntegral componentSets the % integral component of the controller. Default setting is suitable for most heating control systems (typically flow temperature control with a three-way mixer). For more complex control systems such as a heating circuit with an exchanger this parameter may need to be adjusted.
SmStop behaviourThis parameter controls what happens when the stop input is active:
0 = Unchanged
1 = Open
2 = Close
MSets the mixing mode0 = Normal
1 = Inverse (the open output Q1 is considered colder)
MinMinimum output valueSets the minimum output value in percent. So if this value is set to 20 the smallest allowable value of AQ would be 2.
MaxMaximum output valueSets the maximum output value in percent. So if this value is set to 50 the smallest allowable value of AQ would be 5.