Siemens CU230P-2 HVAC Parameter Manual page 441

Symbols for logic functions
Logical inversion
1
AND element
&
with logical inversion of an input signal
OR element
1
x
Exclusiv-OR/XOR
1
y
=1
y = 1 when x1 != x2 is.
x
2
R/S flip-flop
S Q
S = setting input
R = reset input
R Q Q = non-inverted output
Q = inverted output
Symbols for computational and closed-loop control functions
Sign reversal
x y
-1
y = -x
Absolute value generator
x y
y = |x|
Divider
x
1
y
x
1
y =
x
2
x
2
Comparator
x y
>0
Output y = a logical "1", if the analog signal
x > 0, i.e. is positive.
Differentiator
dx
y
x
dx
dt
y =
dt
Symbol for monitoring
Axxxxx
Monitoring
Monitoring or
Fxxxxx
1 2
Explanations for the function diagrams
Explanation of the symbols (Part 2)
Symbols for computational and closed-loop control functions
3 4
S
Threshold value switch 1/0
1
y
x
Outputs at y a logical "1" if x < S.
0
S
Threshold value switch 0/1
1
y
x
Outputs at y a logical "1" if x > S.
0
S
Threshold value 1/0 with hysteresis
1
y
x
Outputs a logical "1" at y if x < S.
If x >= S + H then y returns to 0.
0
H
S
Threshold value 0/1 with hysteresis
1
Outputs a logical "1" at y if x > S.
y
x
If x <= S - H then y returns to 0.
0
Limiter
H
LU MLU
x is limited to the upper limit LU and the lower limit LL
and output at y.
x y
or
The digital signals MLU and MLL have the value "1", if
the upper or lower limit is active.
LL MLL
Sample & Hold element
SET
Sample and hold element.
S & H
x y
y = x if SET = 1
(not retentively saved at POWER OFF)
5 6
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Function diagram
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G120 CU230P-2