3 Functionality for Burner Technology
3.3 Function for controlling the air damper(s) (F_AIRD)
Burner application example for TIA Portal
Item-ID: 109477036, V1.0.2, 08/2015
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The close command (CLOSE_1 = TRUE) is carried out until the feedback signal
AD_CLOSED is detected (AD_CLOSED = TRUE).
If the command to close the air damper is TRUE (CLOSE_ AD = TRUE), the timer
T1_CLOSE is started.
The output CLOSE_1 is reset if the air damper is closed (AD_CLOSED = TRUE)
within the parameterized time of T1_CLOSE. The output CLOSE_2 remains set to
1-Signal as long as the command to close air damper remains true (CLOSE_AD =
TRUE).
If the air damper doesn`t close within the parameterized time, the output
CLOSING_ERROR is set to 1-Signal to display an error at the air damper and fuel
valves.
Drive to Ignition Position
If AD_IGNPOS is set, the inputs CLOSE_AD and OPEN_AD are not evaluated.
The command for controlling the ignition position of the output OPEN_1 is set when
the damper has taken a position below the defined maximum but not above the
defined minimum (AD_MAX = TRUE and AD_MIN = FALSE). If the position of the
damper is above the defined maximum and above the defined minimum (AD_MAX
= FALSE and AD_MIN = TRUE), the output CLOSE_1 is set.
If the ignition position is reached (AD_MIN = TRUE and AD_MAX = TRUE), and
the ignition position is energized (AD_IGNPOS = TRUE), and no error exists
(POS_ERROR = FALSE, CLOSING_ERROR = FALSE and OPENING_ERROR =
FALSE).then this is shown at the output AD_IGNPOS_OK
Error Detection and Reaction
If closing or opening of the (air) damper is not possible within the parameterized
time (T1_CLOSE or T2_OPEN), the output CLOSING_ERROR or
OPENING_ERROR is set to indicate an error at the dampers / fuel valves.
POS_ERROR is set if at least one of the following conditions is met:
The open and closed status of the dampers/valves is reported at the same time
(AD_OPENED und AD_CLOSED at the same time TRUE)
The ignition positon is energized (AD_IGNPOS = TRUE) and both AD_MIN
and AD_MAX have 0-Signal
If an error was detected (POS_ERROR, CLOSING_ERROR or OPENING_ERROR
have 1-Signal), the outputs OPEN_1 and CLOSE_1 are no longer activated and
set to 0-Signal until the error is corrected. CLOSING_ERROR blocks CLOSE_1,
OPENING_ERROR blocks OPEN_1 and POS_ERROR blocks both
CLOSING_ERROR and OPEN_ERROR.
OPEN_2 and CLOSE_2 are not affected by errors. The air damper can be moved
in a safe state by the outputs OPEN_2/CLOSE_2 in case of an error (see chapter
4.3.4).
Quit
If the system has detected an error, the error has to be acknowledged. The error
messages are reset by a rising edge at the input QUIT (CLOSING_ERROR =
FALSE, OPENING_ERROR=FALSE and POS_ERROR = FALSE).
3.3.4 Time diagram
The figure below illustrates the signal sequence of the function F_AIRD.