Parameter description:
The following values can change the equipment characteristics
and are therefore to be set with utmost care.
A1: Switch mode contact K1
A2: Switch mode contact K2
The switch mode for the relays, i.e. cooling or heating function, can be programmed independently at works.
Heating function means that the contact opens as soon as the setpoint is reached, thus power interruption.
At cooling function the contact closes, if the actual value is above the required setpoint. (see fig. 1 + 2)
A3: Function of contact K1 at sensor error
A4: Function of contact K2 at sensor error
At sensor error the selected relay falls back into the condition pre-set here. If there is a data-loss in
parameter memory (display indicates “EP”) both contacts K1 and K2 are switched off.
A5: Selection setpoint 2 or DeltaW
This parameter determines whether the setpoints for thermostat 1 and 2 independently adjustable (A5=0) or
whether they are tied with one another via a switching offset DeltaW (A5=1). This parameter applies only to
contact K2 (see parameter P1).
A8: Display mode
The value can be indicated in integrals or with decimals and if there is a leading zero. In general, all
parameter indications are presented with decimals.
A9: Weighing factor
With this parameter the actual value can be submitted to weighing. The measured value is multiplied by it
and both indicated in the display and applied for regulation.
A10: Indication value for lower value linear analogue input
A11: Indication value for upper value linear analogue input
Only relevant, if the controller is programmed for a voltage input (0…10V linear) or a current input (4…20mA
linear). These parameters allow scaling of the linear analogue input. The value to be indicated for the lower
and upper entrance value then defines the range the controller will indicate. For input range 4…20mA the
display will show sensor error if the input signal drops below 4mA.
A19: Parameter lock
This parameter enables locking of each parameter level. If third level is locked, only parameter A19 may be
changed.
A30: Function alarm exit
The alarm exit evaluates an upper and a lower limit value (see parameters P30 and P31), whereas a
selection is possible as to whether the alarm is active if the temperature lies within these two limits (range
alarm), or whether the alarm is released if the temperature lies beyond them (boundary alarm). In the case of
sensor error, the alarm is activated independently of this adjustment.
A31: Special function at boundary or range alarm
Here can be selected whether, in the case of an alarm, the indication to flash and/or the buzzer is to start.
Sensor alarm (display F1L or F1H) is indicated independently thereof by flashing display and the buzzer.
A32: Setpoint display
A32=0 indicates the actual value, A32=1 statically indicates the setpoint S1 or S1’ in the display. Therefore,
the current actual value can only be indicated with parameter P0.
A33: Adjustment of setpoint S1‘ (not available on all types of controllers)
By closing switching input E1, setpoint S1 can be switched to a setpoint S1’. Setpoint S1’ can be either
relative to setpoint S1 or an independent, freely adjustable, control setting.
The setpoint S1’ can only be accessed if input E1 is closed.
Summary of Contents for ST72-31.03
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