Logic function
86
Example:
The heating circuit is to be released based on the two thermostat functions "comparison_1" and
"comparison_2" when one of the two (OR-function) is triggered. When this function was called, the
number of input variables was already set at two. The following parameters are now set in the sub-
menu
INPUT VARIABLE
:
INPUT VARIABLE 1:
Source: COMP.1
1 : Va > Vb + diff
Input variable 1 is the output of the thermostat function COMP.1
Mode: normal
Adoption of normal start condition of the module
Status: ON
We see current status ON
INPUT VARIABLE 2:
Source: COMP.2
1 : Va > Vb + diff
Input variable 2 is the output of the thermostat function COMP.2
Mode: normal
Adoption of normal start condition of the module
Status: OFF
We see current status OFF
Thus, the function forms the command ON as the output variable. In the function
heating circuit con-
trolr
, it now allows the release of the pump as an input variable if either the "boiler thermostat"
or
the
"buffer thermostat" has exceeded the required temperature.
Value table based on two enable:
AND
Enable:
Input 1:
Input 2:
Result:
Inv. result
Commentary:
ON OFF
OFF OFF
ON
ON ON
OFF OFF
ON
ON OFF
ON OFF
ON
ON ON
ON ON
OFF
OFF
X
X
OFF
OFF
Both outputs OFF
OR
Enable:
Input 1:
Input 2:
Result:
Inv. result
Commentary:
ON OFF
OFF OFF
ON
ON ON
OFF ON
OFF
ON OFF
ON ON
OFF
ON ON
ON ON
OFF
OFF
X
X
OFF
OFF
Both outputs OFF
FLIP FLOP
Enable:
Input 1:
Input 2:
Result:
Inv. result
Commentary:
ON OFF
OFF OFF
ON
Previous status
ON
ON
OFF
ON
OFF
I1 is saved!
ON OFF
OFF ON
OFF
Previous
status
ON
OFF
ON
OFF
ON
I2 deletes output
ON ON
ON OFF
ON
I2
dominant
OFF X
X OFF
OFF
Both outputs OFF
OFF
Enable:
Input 1:
Input 2:
Result:
Inv. result
ON X
X OFF
ON
OFF
X
X
OFF
OFF
Both outputs OFF
