ABB i-bus EIB, Руководство по эксплуатации продукта

Страница: 36 / 62

ABB i-bus
®
EIB / KNX
Project design and programming
4.3.8 Parameter window:
“Threshold”
The threshold function enables the evaluation of a 1-byte or 2-byte object.
As soon as the object value falls below or exceeds a threshold value, a
switching operation can be triggered. Up to two independent threshold
values are available in total. The parameter window is enabled under “A:
Function”.
Explanations about the threshold value function can be found in section
3.2.5. Please note the function diagram in section 3.2.6.
Parameter: “Data type of object ‘Threshold value’”
The data type of the object “Threshold value” can be defined here. It is
possible to choose between a 1-byte integer value and a 2-byte floating
point value.
Parameter: “Threshold value 1” and “Threshold value 2”
Two threshold values can be defined here. If they are not required, it is
possible to enter zero here. The value range is dependent on the data type.
Parameter: “Object value on bus voltage recovery”
The value of the object “Threshold value” after bus voltage recovery can be
defined here.
Note: When a threshold value is exceeded
- the time functions are restarted
- the logic operations are re-evaluated
Parameter: “Threshold values define hysteresis”
This parameter defines whether the 1st and 2nd threshold values should be
interpreted as hysteresis limits. The hysteresis can reduce unwanted
violations of the threshold value if the input value fluctuates around one of
the threshold values.
Parameter: “Object value < lower threshold”
Parameter: “Lower thrsh. <= object < upper thrsh.”
Parameter: “Object value >= upper threshold”
These parameters are visible if the threshold values are not hysteresis limits.
They define the reaction dependent on the threshold value.
The possible reaction of the output is: ON, OFF, no reaction
© 2004 ABB STOTZ-KONTAKT GmbH 36