ABB i-bus KNX Room Master Premium RM/S 2.1, Руководство по эксплуатации продукта

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ABB i-bus
®
KNX
Planning and application
© 2008 ABB STOTZ-KONTAKT GmbH 264
4.9.2 Cooling down
If the new valve position is less than the current position during cooling
down, the contact will open immediately.
The opening time is calculated from:
•
T
down
= Valve adjustment duration from 100 to 0 %
•
V
cur
= Current valve position [0…255]
•
V
new
= New valve position [0…255]
•
T
new
= Switch off time of the PWM at the new valve position
•
T
cyc
= PWM cycle time
•
T
+1
= Is added on the way to V
new
at every position
passed through
Calculation of the opening time
( )
new
cyc
new
V
T
T
−
=
255 * 255
255
255
*
255
1
cur down
V T
T
−
=
+
Calculation of the opening time at switchover
[ ]
( )
[ ]
( )
[ ]
( )
new cur cur new
atV T atV T atV T T T
1 ... 1 1
1
+ + +
+ + + + + =
This means:
•
For a movement from 99…0 % the contact remains opened for about
T
down
+ T
cyc
.
•
For a change in the lower % range it results in significantly
shorter opening times than for changes in the upper % range.
•
Thereafter the contact is opened in accordance with the new PWM cycle
and the PWM cycle is started.