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Valve outputs | Channel-independent functions
In addition, valve outputs, which receive preset command values via the data
format "Switching (1-bit)" and "Switching (1-byte) with command value limiting
value", influence the heat requirement control. In the case of "Switching (1-
bit)", an "OFF" command value is interpreted as "0%" and an "ON" command
value as "100%". In the case of "Switching (1-byte) with command value limit-
ing value", the actuator evaluates the converted switching output signal in the
same way ("OFF" is interpreted as "0%", "ON" is interpreted as "100%").
With some functions and events, valve outputs, which are configured to the
command value data formats "Switching (1-bit)" and "Switching (1-byte) with
command value limiting value", are always activated via a constant command
value through pulse width modulation (PWM), providing that command values
not equal to 0% or 100% are to be set (after bus voltage return, after an ETS
programming operation, during manual operation, with an active forced posi-
tion and with active emergency operation). PWM keeps being executed until
the named functions have been exited or, after the named events, no more
lower-level functions are active and a new command value telegram is re-
ceived via the bus, overriding the constant command value on the valve out-
put.
In this case, the constant command value set by the PWM is also included in
the heat requirement control.
After bus voltage return and an ETS programming operation, the actuator al-
ways first transmits the status "No heat requirement" without a delay. The ac-
tuator then updates the status to "Heat requirement", providing that the condi-
tion for this has been fulfilled and an optionally configured "Heat requirement
ACTIVE" has elapsed.
A valve output affected by a short-circuit / overload (valve completely closed
on deenergised closed or completely opened on deenergised opened) does
not influence the heat requirement control.
Image 5: Heat requirement information with sample command value characteristic
Heating actuator 6-gang with controller | Order no. 2139 00 | 21393100
Page 40 of 257
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