6. Function blocks
6.1 Manufacturer function blocks
Parameter set
Description Note
Function block release by
EN is necessary
If this checkbox is enabled, the state
of function block input EN will be
evaluated. If the checkbox is dis-
abled instead, the function block will
be enabled and function block input
EN will not do anything.
This parameter ensures that
when existing programs are
copied, the functionality of the
function blocks that are carried
over will be retained. The para-
meter will be automatically set
to 0 or 1 depending on the func-
tion block.
Parameter display
+ Call enabled
Function block parameters and con-
stants can be edited on the device.
Simulation possible
Other
Retention
The function block does not recognize retentive data.
Heating and cooling
Actual value I1 (temperature) is higher than setpoint I2, meaning that cooling is
required.
Function block output Q1 =1 switches the cooling system on as soon as (I1-I2) > XH.
Actual value I1 (temperature) is lower than setpoint I2, meaning that heating is required.
Function block output Q2 = 1 switches the heating system on as soon as (I1-I2) > XH
Hysteresis values H1 and H2 determine how long cooling or heating is required and,
accordingly, the cooling/heating energy content.
Figure 159: Signal diagram for three-step controller
300
easyE4 11/18 MN050009 EN www.eaton.com